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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 SCHEDULE 13D/A

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                                (AMENDMENT NO. 2)

                               AGERE SYSTEMS INC.
                   -------------------------------------------
                                (Name of Issuer)

               CLASS A COMMON STOCK, PAR VALUE $0.01 PER SHARE
                         (Title of Class of Securities)

                                   00845V 10 0
                                 ---------------
                                 (CUSIP Number)
         -----------------------------------------------------------

                                SCOTT A. ARENARE
                      MANAGING DIRECTOR AND GENERAL COUNSEL
                               WARBURG PINCUS LLC
                              466 LEXINGTON AVENUE
                            NEW YORK, NEW YORK 10017
                                 (212) 878-0600
         -----------------------------------------------------------
           (Name, Address and Telephone Number of Person Authorized
                    to Receive Notices and Communications)

                                 WITH A COPY TO:
                              ANDREW R. BROWNSTEIN
                         WACHTELL, LIPTON, ROSEN & KATZ
                               51 WEST 52ND STREET
                            NEW YORK, NEW YORK 10019
                                 (212) 403-1000


                                  OCTOBER 16, 2002
          ----------------------------------------------------------
           (Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition that is the subject of this Schedule 13D, and is filing this
schedule because of ss.ss. 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check
the following box: [_].

                                Page 1 of 9 Pages

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   1          NAME OF REPORTING PERSON
              I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
                     WARBURG PINCUS PRIVATE EQUITY VIII, L.P.
                     I.R.S. IDENTIFICATION NO. 13-4161869

-------------------------------------------------------------------------------
   2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                       (a)  [X]
                                                                       (b)  [ ]

-------------------------------------------------------------------------------
   3          SEC USE ONLY                                                  [ ]
-------------------------------------------------------------------------------

   4          SOURCE OF FUNDS
                    WC

-------------------------------------------------------------------------------
   5          CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
              PURSUANT TO ITEMS 2(d) OR 2(e)
                                                                            [ ]

-------------------------------------------------------------------------------
   6          CITIZENSHIP OR PLACE OF ORGANIZATION
                    DELAWARE
-------------------------------------------------------------------------------
  NUMBER OF    7
                   SOLE VOTING POWER
   SHARES                -0-
               ----------------------------------------------------------------
BENEFICIALLY   8
                   SHARED VOTING POWER
  OWNED BY               69,386,961*
               ----------------------------------------------------------------
    EACH
               9
  REPORTING        SOLE DISPOSITIVE POWER
                         -0-
 PERSON WITH   ----------------------------------------------------------------
               10
                   SHARED DISPOSITIVE POWER
                         69,386,961*
-------------------------------------------------------------------------------

     11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                    69,386,961*
-------------------------------------------------------------------------------
     12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
              SHARES                                                        [ ]
-------------------------------------------------------------------------------
     13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
                    9.0%**
-------------------------------------------------------------------------------
     14       TYPE OF REPORTING PERSON
                    PN
-------------------------------------------------------------------------------


--------------------------
* Assumes the full conversion of the Convertible Subordinated Notes beneficially
  owned by the Investors in accordance with their terms.
**Represents the percentage of Class A Common Stock beneficially owned by
  WP VIII as of October 17, 2002 assuming full conversion of the Convertible
  Subordinated Notes beneficially owned by the Investors in accordance with
  their terms. Based on the same assumption, as of October 17, 2002, WP VIII
  beneficially owned 4.1% of the outstanding Class A Common Stock and Class B
  Common Stock, taken as a whole.


                                 Page 2

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   1          NAME OF REPORTING PERSON
              I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
                    WARBURG, PINCUS & CO.
                    I.R.S. IDENTIFICATION NO. 13-6358475
-------------------------------------------------------------------------------
   2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                       (a)  [X]
                                                                       (b)  [ ]
-------------------------------------------------------------------------------
   3          SEC USE ONLY                                                  [ ]
-------------------------------------------------------------------------------
   4          SOURCE OF FUNDS
                    WC
-------------------------------------------------------------------------------
   5          CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
              PURSUANT TO ITEMS 2(d) OR 2(e)                                [ ]
-------------------------------------------------------------------------------
   6          CITIZENSHIP OR PLACE OF ORGANIZATION
                    NEW YORK
-------------------------------------------------------------------------------
  NUMBER OF    7
                   SOLE VOTING POWER
   SHARES                -0-
               ----------------------------------------------------------------
BENEFICIALLY   8
                   SHARED VOTING POWER
  OWNED BY               69,386,961*
               ----------------------------------------------------------------
    EACH       9
                   SOLE DISPOSITIVE POWER
  REPORTING              -0-
               ----------------------------------------------------------------
 PERSON WITH   10
                   SHARED DISPOSITIVE POWER
                         69,386,961*
-------------------------------------------------------------------------------
     11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                    69,386,961*
-------------------------------------------------------------------------------
     12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
              SHARES                                                        [ ]
-------------------------------------------------------------------------------
     13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
                    9.0%**
-------------------------------------------------------------------------------
     14       TYPE OF REPORTING PERSON
                    PN
-------------------------------------------------------------------------------


-----------------------------
* Assumes the full conversion of the Convertible Subordinated Notes beneficially
  owned by the Investors in accordance with their terms.
**Represents the percentage of Class A Common Stock beneficially owned by WP
  as of October 17, 2002 assuming full conversion of the Convertible
  Subordinated Notes beneficially owned by the Investors in accordance with
  their terms. Based on the same assumption, as of October 17, 2002, WP
  beneficially owned 4.1% of the outstanding Class A Common Stock and Class B
  Common Stock, taken as a whole.


                                 Page 3

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   1          NAME OF REPORTING PERSON
              I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
                    WARBURG PINCUS LLC
                    I.R.S. IDENTIFICATION NO. 13-3536050

-------------------------------------------------------------------------------
   2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                       (a)  [X]
                                                                       (b)  [ ]
-------------------------------------------------------------------------------
   3          SEC USE ONLY                                                  [ ]
-------------------------------------------------------------------------------
   4          SOURCE OF FUNDS
                    WC
-------------------------------------------------------------------------------
   5          CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
              PURSUANT TO ITEMS 2(d) OR 2(e)                                [ ]
-------------------------------------------------------------------------------
   6          CITIZENSHIP OR PLACE OF ORGANIZATION
                    NEW YORK
-------------------------------------------------------------------------------
  NUMBER OF   7
                   SOLE VOTING POWER
   SHARES                -0-
              -----------------------------------------------------------------
BENEFICIALLY  8
                   SHARED VOTING POWER
  OWNED BY              69,386,961*
              -----------------------------------------------------------------
    EACH      9
                   SOLE DISPOSITIVE POWER
  REPORTING             -0-
              -----------------------------------------------------------------
 PERSON WITH  10
                   SHARED DISPOSITIVE POWER
                        69,386,961*
-------------------------------------------------------------------------------
     11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                    69,386,961*
-------------------------------------------------------------------------------
     12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
              SHARES                                                        [ ]
-------------------------------------------------------------------------------
     13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
                    9.0%**
-------------------------------------------------------------------------------
     14       TYPE OF REPORTING PERSON
                    OO
-------------------------------------------------------------------------------


-------------------------
* Assumes the full conversion of the Convertible Subordinated Notes beneficially
  owned by the Investors in accordance with their terms.
**Represents the percentage of Class A Common Stock beneficially owned by
  WP LLC as of October 17, 2002 assuming full conversion of the Convertible
  Subordinated Notes beneficially owned by the Investors in accordance with
  their terms. Based on the same assumption, as of October 17, 2002, WP LLC
  beneficially owned 4.1% of the outstanding Class A Common Stock and Class B
  Common Stock, taken as a whole.


                                  Page 4


                                AMENDMENT NO. 2 TO

                                  SCHEDULE 13D

            Reference is made to the statement on Schedule 13D filed on
June 21, 2002 and Amendment No. 1 thereto filed on July 29, 2002 (as so
amended, the "Schedule 13D") on behalf Warburg Pincus Private Equity VIII, L.P.,
a limited partnership organized under the laws of Delaware ("WP VIII"),
Warburg, Pincus & Co., a general partnership organized under the laws of New
York ("WP"), and Warburg Pincus LLC, a limited liability company organized under
the laws of New York ("WP LLC", and together with WP VIII and WP, the "Reporting
Persons"). All capitalized terms used without definition herein have the
meanings ascribed thereto in the Schedule 13D. This Amendment No. 2 to the
Schedule 13D amends the Schedule 13D as follows.

ITEM 3.     SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.
            --------------------------------------------------

Item 3 of the Schedule 13D is amended and supplemented by adding the following:

            The total amount of funds required by the Investors to purchase the
Convertible Subordinated Notes (as defined below) on October 4, 7, 9 and 16,
2002 as described under Item 5(c) below was, and the total amount of funds
required by the Investors to purchase the Additional Convertible Subordinated
Notes as described under Item 5(c) will be, furnished from the committed capital
of the Investors. The total amount of funds used by the Investors to purchase
such Convertible Subordinated Notes on October 4, 7, 9 and 16, 2002 was
$14,882,825. The total amount of funds that will be used by the Investors to
purchase the Additional Convertible Subordinated Notes cannot be determined at
this time.

ITEM 5.     INTEREST IN SECURITIES OF THE ISSUER.
            -------------------------------------

Item 5 of the Schedule 13D is amended and restated to read as follows:

(a)  The Reporting Persons beneficially own shares of Class A Common Stock by
     virtue of the Investors' beneficial ownership of shares of Class A Common
     Stock and of the Issuer's 6.5% Convertible Subordinated Notes due 2009 (the
     "Convertible Subordinated Notes"), which are convertible at the option of
     the holder into 302.34 shares of Class A Common Stock per $1,000 principal
     amount of Convertible Subordinated Notes, subject to adjustment in certain
     circumstances. As of October 17, 2002, the Reporting Persons beneficially
     owned an aggregate of 69,386,961 shares of Class A Common Stock,
     representing 33,650,000 shares of Class A Common Stock beneficially owned
     by the Investors and 35,736,961 shares of Class A Common Stock that may be
     acquired by the Investors upon full conversion of the Convertible
     Subordinated Notes beneficially owned by the Investors. Of the aggregate of
     69,386,961 shares of Class A Common Stock beneficially owned by WP and WP
     LLC, 2,144,057 shares represent shares of Class A Common Stock owned of
     record by WPNPE VIII I, WPNPE VIII II and WPGPE VIII. By reason of WP's and
     WP LLC's respective relationships with the Investors, under Rule 13d-3 of
     the Exchange Act, WP and WP LLC may be deemed to beneficially own all of
     the shares of Class A Common Stock that are beneficially owned by the
     Investors.

                                       5



     Assuming full conversion of the Convertible Subordinated Notes beneficially
     owned by the Investors, as of October 17, 2002, the 69,386,961 shares of
     Class A Common Stock beneficially owned by each Reporting Person
     represented approximately 9.0% of the outstanding shares of Class A Common
     Stock, and 4.1% of the Issuer's outstanding shares of Class A Common Stock
     and Class B Common Stock, par value $0.01 per share (the "Class B Common
     Stock"), taken as a whole, in each case, after giving effect to the
     issuance of the Class A Common Stock upon full conversion of the
     Convertible Subordinated Notes beneficially owned by the Investors (based
     on 731,348,289 shares of Class A Common Stock and 907,955,677 shares of
     Class B Common Stock outstanding as of July 31, 2002, as set forth in the
     Issuer's Form 10-Q for the quarterly period ended June 30, 2002).

(b)  As described in paragraph (a) above, the Group Members have beneficial
     ownership over an aggregate of 69,386,961 shares of Class A Common Stock.
     Of this aggregate of 69,386,961 shares of Class A Common Stock, 33,650,000
     shares are represented by the shares of Class A Common Stock beneficially
     owned by the Investors and 35,736,961 are represented by shares of Class A
     Common Stock that are issuable to the Investors upon full conversion of the
     Convertible Subordinated Notes beneficially owned by the Investors. Each of
     the Investors shares voting power and dispositive power over the shares of
     Class A Common Stock that such Investor beneficially owns with WP LLC and
     WP.

(c)  The Investors acquired shares of Class A Common Stock in the open
     market transactions described below:
                                                          Total Cost (net of
          Date         # of Shares     Per Share Price    brokerage commissions)
      ------------     ------------    ---------------    ----------------------
         1/31/02          270,000           $5.08             $1,371,789
         2/1/02           730,000           $5.10             $3,723,000
         2/4/02         1,000,000           $5.06             $5,062,500
         2/5/02         1,460,000           $4.10             $5,982,204
         6/11/02        1,000,000           $2.65             $2,647,100
         6/12/02        9,720,000           $2.37            $23,059,728
         6/13/02        5,700,000           $2.40            $13,660,620
         6/27/02        2,770,000           $1.50             $4,155,637

      On June 13, 2002, the Investors agreed to purchase Convertible
      Subordinated Notes with an aggregate principal amount of $75,000,000 in an
      underwritten public offering.

      On July 29, 2002, the Investors settled the Forward Contract by accepting
      delivery from Citibank of 11,000,000 shares of Class A Common Stock for
      aggregate consideration of $24,671,700, net of brokerage commissions and
      other transaction costs.

      The Investors acquired Convertible Subordinated Notes with an aggregate
      principal amount of $30,700,000 in brokered transactions as described
      below:


                                        Price (% of
          Date          Aggregate     Principal  Amount)        Total Cost
                        Principal     (in each case plus     (including accrued
                         Amount        accrued interest)        interest)
      ------------   ---------------   ----------------      ------------------

         10/4/02        $5,000,000         45.150%            $2,356,806
         10/7/02        $4,000,000         42.896%            $1,796,007
         10/8/02       $14,200,000         43.114%            $6,409,370
        10/16/02        $7,500,000         55.406%            $4,320,643


                                       6



      On October 16, 2002, the Investors agreed to purchase additional
      Convertible Subordinated Notes (the "Additional Convertible Notes") with
      an aggregate principal value of $12,500,000 from Salomon Smith Barney (the
      "Broker"). The prices to be paid by the Investors for these additional
      Convertible Subordinated Notes cannot be determined at this time but will
      be equal to a premium of 27% of the principal amount thereof plus the
      Parity Amount (as defined below) thereof. The "Parity Amount" of the
      Additional Convertible Subordinated Notes is an amount (expressed as a
      percentage of the principal amount of the Additional Convertible
      Subordinated Notes) equal to the product of (1) the number of shares of
      Class A Common Stock into which the Additional Convertible Subordinated
      Notes may be converted, times (2) the average per share cost to the Broker
      of a number of shares of Class A Common Stock purchased by the Broker in
      connection with the transaction, with the number of shares of Class A
      Common Stock to be purchased to be determined by the Broker in
      accordance with its risk management procedures. The closings of the
      purchase of these Additional Convertible Subordinated Notes will occur
      from time to time based on market conditions, as determined by
      the Broker. The 3,779,289 shares of Class A Common Stock into which the
      Additional Convertible Subordinated Notes may be converted are included
      in the 69,386,961 shares of Class A Common Stock beneficially owned by
      the Investors.

      Except as described herein, during the last sixty days there were no
      transactions in shares of Class A Common Stock effected by the Reporting
      Persons or, to the best of their knowledge, by any of the persons set
      forth on Schedule I.

(d)  Except as set forth in this Item 5, no person other than each respective
     record owner referred to herein of the shares of Class A Common Stock is
     known to have the right to receive or the power to direct the receipt of
     dividends from, or the proceeds from the sale of, such shares of Class A
     Common Stock.

(e) Not applicable


ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO
        ------------------------------------------------------------------------
        SECURITIES OF THE ISSUER.
        -------------------------

Item 6 of the Schedule 13D is amended and supplemented by adding the following:

            See Item 5(c) for a description of an agreement between the
Investors and the Broker with respect to the purchase of the Additional
Convertible Subordinated Notes.


                                        7


                                   SIGNATURES


            After reasonable inquiry and to the best of our knowledge and
belief, the undersigned certify that the information set forth in this statement
is true, complete and correct.

Dated:  October 17, 2002


                               WARBURG PINCUS PRIVATE EQUITY VIII, L.P.

                              By: Warburg, Pincus & Co.,
                                  General Partner

                                  By: /s/ Scott A. Arenare
                                      ----------------------------------------
                                        Name:  Scott A. Arenare
                                        Title: Partner


                              WARBURG, PINCUS & CO.

                              By:  /s/ Scott A. Arenare
                                  --------------------------------------------
                                  Name:  Scott A. Arenare
                                  Title: Partner


                              WARBURG PINCUS LLC

                              By:  /s/ Scott A. Arenare
                                   -------------------------------------------
                                  Name:  Scott A. Arenare
                                  Title: Member


                              WARBURG PINCUS NETHERLANDS PRIVATE EQUITY VIII
                                 C.V. I

                               By: Warburg, Pincus & Co.,
                                   General Partner

                                  By: /s/ Scott A. Arenare
                                      ----------------------------------------
                                        Name:  Scott A. Arenare
                                        Title: Partner


                                       8




                               WARBURG PINCUS NETHERLANDS PRIVATE EQUITY VIII
                                     C.V. II

                               By: Warburg, Pincus & Co.,
                                   General Partner

                                  By: /s/ Scott A. Arenare
                                      ----------------------------------------
                                        Name:  Scott A. Arenare
                                        Title: Partner


                               WARBURG PINCUS GERMANY PRIVATE EQUITY VIII KG

                               By: Warburg, Pincus & Co.,
                                   General Partner

                                  By: /s/ Scott A. Arenare
                                      ----------------------------------------
                                        Name:  Scott A. Arenare
                                        Title: Partner