Filed by Sanofi-Aventis
                                  Pursuant to Rule 165 and Rule 425(a) under the
                                           United States Securities Act of 1933,
                                                                      as amended

                                                        Subject Company: Aventis
                                                   Commission File No. 001-10378
                                                        Date: September 16, 2004


         On September 16, 2004, Sanofi-Aventis issued the following press
release.

         In  connection   with  its   acquisition  of  Aventis,   Sanofi-Aventis
(previously  known  as  Sanofi-Synthelabo)  has  filed  with the  United  States
Securities and Exchange  Commission (SEC), a registration  statement on Form F-4
(File no: 333-112314),  which includes a prospectus and a prospectus  supplement
relating to the revised offer, and related exchange offer materials, to register
the  Sanofi-Aventis  ordinary shares (including  Sanofi-Aventis  ordinary shares
represented  by  Sanofi-Aventis  ADSs) to be  issued  in  exchange  for  Aventis
ordinary  shares  held by holders  located in the United  States and for Aventis
ADSs  held by  holders  wherever  located  and has  also  filed  with  the SEC a
Statement  on  Schedule  TO.  INVESTORS  AND HOLDERS OF AVENTIS  SECURITIES  ARE
STRONGLY  ADVISED TO READ THE  REGISTRATION  STATEMENT  AND THE  PROSPECTUS  AND
PROSPECTUS  SUPPLEMENT  RELATING TO THE REVISED OFFER, THE STATEMENT ON SCHEDULE
TO,  AND ANY  OTHER  RELEVANT  DOCUMENTS  FILED  WITH  THE  SEC,  AS WELL AS ANY
AMENDMENTS AND SUPPLEMENTS BECAUSE THEY CONTAIN IMPORTANT INFORMATION. Investors
and holders of Aventis  securities  may obtain  free copies of the  registration
statement,  the prospectus,  the prospectus  supplement  relating to the revised
offer and related exchange offer materials, and the Statement on Schedule TO, as
well as other  relevant  documents  filed with the SEC, at the SEC's web site at
www.sec.gov.  The prospectus,  the prospectus supplement relating to the revised
offer and  other  transaction-related  documents  are  being  mailed to  Aventis
securityholders  eligible to participate in the U.S. offer and additional copies
may be obtained for free from MacKenzie  Partners,  Inc., the information  agent
for the U.S. offer, at the following address: 105, Madison Avenue, New York, New
York 10016;  telephone  1-(212)  929-5500  (call  collect)  or 1-(800)  322-2885
(toll-free call); e-mail proxy@mackenziepartners.com.


                                     * * * *





                              [SANOFI-AVENTIS LOGO]
                             BECAUSE HEALTH MATTERS


               FINAL RESULTS OF SANOFI-AVENTIS' OFFER FOR AVENTIS

        AFTER SUBSEQUENT OFFERING PERIOD, SANOFI-AVENTIS HOLDS 98.03% OF
                             AVENTIS SHARE CAPITAL


PARIS,  FRANCE  --  SEPTEMBER  16,  2004 --  Sanofi-Aventis  (formerly  known as
Sanofi-Synthelabo)  (PARIS:  SAN, NYSE:  SNY) announces that the French Autorite
des  marches   financiers  (AMF)  today  published  the  definitive  results  of
Sanofi-Aventis'  offers for Aventis after the subsequent offering periods. These
results  indicate that, as of the expiration of the subsequent  offering periods
on September 6, 2004, in aggregate an  additional  21,397,038  Aventis  ordinary
shares had been  tendered  into the French,  German and U.S.  offers  during the
subsequent  offering periods  (including an additional  709,640 Aventis ordinary
shares  underlying  the Aventis ADSs  tendered  during the  subsequent  offering
period of the U.S. offer).

When  combined  with the  769,920,773  Aventis  shares  tendered into the offers
during the initial  offering  period that ended on July 30, 2004,  these results
indicate that  Sanofi-Aventis  will hold 791,317,811 Aventis shares representing
98.03% of the share capital and 98.09% of the voting rights of Aventis, based on
807,204,134 shares and 806,750,129 voting rights outstanding on August 31, 2004.
After giving effect to the offers, on a fully-diluted basis, Sanofi-Aventis will
hold 92.44% of the share capital and 92.49% of the voting rights of Aventis.

Sanofi-Aventis  will  accept all the  Aventis  ordinary  shares  tendered in the
offers during the subsequent offering periods and expects that the settlement of
the offers and the delivery of the offer  consideration  in accordance  with the
terms of the offers will occur in respect of tendered Aventis ordinary shares on
Friday,  September  24, 2004 and in respect of Aventis ADSs tendered in the U.S.
offer no later than Thursday, September 30, 2004 (to allow for necessary foreign
exchange  conversions).  Euronext  Paris  will  publish  the  timetable  for the
settlement and delivery.



EFFECT OF PRORATION AND ALLOCATION.

According to the AMF's  announcement,  during the subsequent offering period, in
aggregate  12,147,812  Aventis  ordinary  shares were  tendered for the standard
entitlement,  4,771,829 Aventis ordinary shares were tendered pursuant to an all
stock election and 4,477,397  Aventis ordinary shares were tendered  pursuant to
an all cash election.  Because the aggregate  number of Aventis  ordinary shares
tendered  pursuant  to an all  stock  election  was less than  2.5512  times the
aggregate  number of Aventis  ordinary shares  tendered  pursuant to an all cash
election, the all cash election was oversubscribed. After applying the proration
and allocation  procedures in the manner  described in the offer  documentation,
2,606,972 of the Aventis  ordinary  shares  tendered in the subsequent  offering
period  pursuant to all cash elections were deemed to have been tendered for the
standard




entitlement,  with the result  that  Sanofi-Aventis  is  acquiring  the  Aventis
ordinary  shares  tendered in the subsequent  offering  period  according to the
following distribution:

        o    14,754,784 for the standard entitlement;

        o    4,771,829 pursuant to the all stock election; and

        o    1,870,425 pursuant to the all cash election.

As a result of this  allocation  and  proration,  holders that tendered  Aventis
ordinary  shares (or Aventis ADSs) pursuant to an all cash election will receive
the all cash  consideration  of  (euro)68.11  per Aventis  ordinary share (or an
amount in U.S.  dollars equal to (euro)68.11 per Aventis ADS) in respect of only
41.836% of the  Aventis  securities  that they  tendered  during the  subsequent
offering period and will receive the standard entitlement of (euro)19.18 in cash
and 0.8333 of a  Sanofi-Aventis  ordinary share for each Aventis  ordinary share
(or an  amount  in  U.S.  dollars  equal  to  (euro)19.18  in  cash  and  1.6667
Sanofi-Aventis  ADSs in exchange  for each Aventis ADS) in respect of 58.164% of
the Aventis securities that they tendered during the subsequent offering period.
However, it is important to note that these figures do not take into account the
effect  of   fractional   shares  and  reflect  the  effect  of  rounding.   The
consideration  that holders will receive in exchange for Aventis ordinary shares
(or Aventis ADSs) that they tendered for the standard entitlement or pursuant to
an all stock  election will not be subject to any adjustment and will be paid in
the amounts described in the offer documentation.

As previously  disclosed,  the results of the  application  of the proration and
allocation  adjustments to tenders in the subsequent offering period differ from
the results of their application to tenders in the initial offering period ended
July 30, 2004, which were described in our press release dated August 12, 2004.

In  aggregate,  taking into  account the  769,920,773  Aventis  ordinary  shares
acquired in connection with the initial  offering period ended July 30, 2004 and
the 21,397,038  Aventis  ordinary  shares to be acquired in connection  with the
subsequent  offering  period ended September 6, 2004,  Sanofi-Aventis  will have
acquired   791,317,811  Aventis  ordinary  shares  according  to  the  following
distribution:

        o    679,316,145 for the standard entitlement;

        o    80,462,562 pursuant to the all stock election; and

        o    31,539,104 pursuant to the all cash election.

DIVIDEND PAYMENT DATE

Under the terms of the offers,  each  Sanofi-Aventis  ordinary  share  issued to
tendering  holders of Aventis ordinary shares will entitle the holders (provided
they continue to hold the  Sanofi-Aventis  ordinary  shares through  payment) to
receive the  dividend of  (euro)1.02  that the  shareholders  of  Sanofi-Aventis
approved for  distribution  in respect of  Sanofi-Aventis's  2003 results.  This
dividend  will  be  paid  on  September  30,  2004,  to the  holders  of the new
Sanofi-Aventis  ordinary  shares as of the close of  business on  September  29,
2004. An interim  dividend of (euro)0.97 per share has already been  distributed
on the  existing  Sanofi-Aventis  ordinary  shares.  The  balance of  (euro)0.05
remaining  on  the  2003   dividend   will  also  be  paid  on  these   existing
Sanofi-Aventis  ordinary  shares on




September 30, 2004, to whomever  holds those  existing  Sanofi-Aventis  ordinary
shares as of the close of business on September 29, 2004.





STUDY OF MERGER OF AVENTIS WITH AND INTO SANOFI-AVENTIS

As  previously  announced,  following the  acquisition  of control of Aventis by
Sanofi-Aventis  on August 20,  2004,  and in order to create a more  streamlined
legal  structure that better  reflects the  operational  organization of the new
Group, the Board of Directors of Sanofi-Aventis, at a meeting held on August 30,
2004,  authorized the study of a merger of Aventis with and into  Sanofi-Aventis
with  Sanofi-Aventis  continuing as the surviving  corporation in the merger, on
the basis of an exchange ratio of 1.1739 Sanofi-Aventis ordinary shares for each
Aventis  ordinary  share (which is equivalent to exchange  ratio pursuant to the
all share  election  in the  offers,  before the  adjustment  in respect of 2003
Aventis dividend).  The study would contemplate  completion of the merger by the
end of 2004.


In accordance with article 7 of the COB rule no. 2002-04, this press release was
transmitted to the Autorite des marches financiers (AMF) before its publication.



Important Information
---------------------

In  connection  with its  acquisition  of  Aventis,  Sanofi-Aventis  has filed a
registration statement on Form F-4 (File no. 333-112314), including a prospectus
and a  prospectus  supplement  relating  to the  revised  offer,  and will  file
additional  documents with the SEC. INVESTORS ARE URGED TO READ THE REGISTRATION
STATEMENT,  INCLUDING THE PROSPECTUS AND THE PROSPECTUS  SUPPLEMENT  RELATING TO
THE  REVISED  OFFER,  AND ANY  OTHER  RELEVANT  DOCUMENTS  FILED  WITH  THE SEC,
INCLUDING  ALL  AMENDMENTS  AND  SUPPLEMENTS,  BECAUSE  THEY  CONTAIN  IMPORTANT
INFORMATION.  Free  copies  of the  registration  statement,  as well  as  other
relevant  documents filed with the SEC, may be obtained at the SEC's web site at
www.sec.gov.  The  prospectus  and the  prospectus  supplement  relating  to the
revised  offer  and other  transaction-related  documents  have  been  mailed to
Aventis  security  holders  eligible  to  participate  in  the  U.S.  offer  and
additional  copies may be obtained for free from MacKenzie  Partners,  Inc., the
information  agent for the U.S. offer, at the following  address:  105,  Madison
Avenue, New York, New York 10016; telephone:  1-(212) 929-5500 (call collect) or
1-(800) 322-2885 (toll-free call); e-mail proxy@mackenziepartners.com.

In France,  holders of Aventis  securities  are  requested,  with respect to the
offer,   to   refer   to   the   prospectus   supplement   (note   d'information
complementaire),  which has been granted visa number 04-384 by the AMF and which
is  available  on the website of the AMF  (www.amf-france.org)  and without cost
from: BNP Paribas Securities Services,  GIS-Emetteurs,  Service Logistique,  Les
Collines de l'Arche,  75450  Paris Cedex 9 and to the  recommendation  statement
(note d'information en reponse) which has been granted visa number 04-510.

The public offer to holders of Aventis ordinary shares located in Germany (the
"German Offer") has been made in accordance with applicable German law and
pursuant to an offer document/sales prospectus, which is available free of
charge at BNP Paribas Securities Services, Gruneburgweg 14, D-60322 Frankfurt am
Main (Fax: 069 - 152 05 277) and on the website of the Company
(www.sanofi-synthelabo.com

The  French  Offer,  the U.S.  Offer and the  German  Offer  are  being  made on
substantially  the same terms and  completion  of these offers is subject to the
same conditions.  The subsequent offering periods in the three offers expired at
the same time.

This press  release does not  constitute an offer to purchase or exchange or the
solicitation  of an offer to sell or exchange  any  securities  of Aventis or an
offer to sell or exchange or the solicitation of an offer to buy or exchange any
securities  of  Sanofi-Aventis,  nor  shall  there  be any sale or  exchange  of
securities in any jurisdiction  (including the United States, Germany, Italy and
Japan) in which such offer,  solicitation  or sale or exchange would be unlawful
prior to the registration or qualification  under the laws of such jurisdiction.
The distribution of this communication may, in some countries,  be restricted by
law or  regulation.  Accordingly,  persons  who  come  into  possession  of this
document  should  inform  themselves  of and  observe  these  restrictions.  The
Sanofi-Aventis   ordinary  shares  (including   Sanofi-Aventis  ordinary  shares
represented  by  Sanofi-Aventis  ADSs) may not be sold, nor may offers to buy be
accepted,  in the United  States  prior to the time the  registration  statement
becomes effective.  No offering of securities shall be made in the United States
except by means of a prospectus  meeting the  requirements  of Section 10 of the
United States Securities Act of 1933, as amended.

Forward-Looking Statements
--------------------------

This press release  contains  forward-looking  information and statements  about
Sanofi-Aventis,  Aventis and their combined  businesses  after completion of the
acquisition.  Forward-looking  statements are statements that are not historical
facts.  These statements  include financial  projections and estimates and their
underlying assumptions,  statements regarding plans, objectives and expectations
with  respect  to future  operations,  products  and  services,  and  statements
regarding   future   performance.   Forward-looking   statements  are  generally
identified  by  the  words  "expect,"   "anticipates,"   "believes,"  "intends,"
"estimates"  and  similar  expressions.   Although  Sanofi-Aventis'   management
believes that the expectations reflected in such forward-looking  statements are
reasonable,  investors  and holders of Aventis  securities  are  cautioned  that
forward-looking  information  and  statements  are subject to various  risks and
uncertainties,  many of which are difficult to predict and generally  beyond the
control of  Sanofi-Aventis,  that could cause actual results and developments to
differ  materially  from those  expressed  in, or implied or  projected  by, the
forward-looking  information  and  statements.  These  risks  and  uncertainties
include those discussed or identified in the public filings with the SEC and the
AMF made by Sanofi-Aventis and Aventis, including those listed under "Cautionary
Statement  Concerning  Forward-Looking  Statements"  and "Risk  Factors"  in the
prospectus/offer to exchange included in the registration  statement on Form F-4
that Sanofi-Aventis has filed with the SEC (File no: 333-112314).  Other than as
required by applicable law,  Sanofi-Aventis does not undertake any obligation to
update or revise any forward-looking information or statements.

Investors  and  security  holders  may obtain a free copy of the Form 20-F filed
with the SEC on April 2, 2004 and any other  documents



filed by Sanofi-Aventis with the SEC at www.sec.gov and may obtain the Reference
Document filed with the AMF on April 2, 2004 (No.  04-0391) and other  documents
filed  with the AMF at  www.amf-france.org.  Free  copies  may also be  obtained
directly from Sanofi-Aventis on our web site at: www.sanofi-synthelabo.com.





INVESTOR RELATIONS DEPARTMENT
Philippe Goupit                 Director of Investor Relations
Arnaud Delepine                 Investor Relations Europe
Sanjay Gupta                    Investor Relations US
Anne d'Halluin-Sulzer           Investor Relations
Loic Gonnet                     Investor Relations

CONTACTS
E-mail : investor-relations@sanofi-synthelabo.com
Europe                          US
Tel : + 33 1 53 77 45 45        Tel.: + 1 212 551 40 18
Fax : + 33 1 53 77 42 96        Fax : + 1 646 487 40 18