GTC Biotherapeutics to Host Third Quarter 2009 Earnings Call on November 6, 2009 and Webcast the Merriman Investor Summit Presentation on November 10, 2009

GTC Biotherapeutics, Inc. (Nasdaq: GTCB) (“GTC”) announced today that its financial results for the third quarter 2009 will be released on Friday, November 6, 2009 followed by a webcast conference call starting at 10:00 a.m. Eastern Time. You may access the live internet broadcast or the subsequent archived recording, on GTC’s website at http://www.gtc-bio.com or access the conference call as follows:

NOTE: a replay of the call will be available one hour following the end of the call and will be accessible until November 23, 2009 at 11:59 PM.

In addition, Geoffrey Cox, Ph.D., GTC’s Chairman and CEO, is scheduled to present on Tuesday, November 10, 2009 at 10:40 a.m. during the Merriman Investor Summit 2009. The conference is being held at the Sofitel Hotel in New York, New York on November 10, 2009. More information about the conference can be found at www.mdfco.com.

The presentation will be webcast live and can be accessed by logging onto www.gtc-bio.com. The replay can be accessed from this same website and will be available within 24 hours of the presentation.

About GTC Biotherapeutics

GTC Biotherapeutics develops, supplies and commercializes therapeutic proteins produced through transgenic animal technology. ATryn®, GTC’s recombinant human antithrombin, has been approved for use in the United States and Europe. ATryn is the first and only product produced in transgenic animals to be approved for therapeutic use anywhere in the world. In addition to ATryn, GTC is developing a portfolio of recombinant human plasma proteins with known therapeutic properties. These proteins include recombinant forms of human coagulation factors VIIa and IX, which are being developed for the treatment of hemophilia. GTC is also developing a portfolio of follow-on biologic monoclonal antibodies and a CD20 antibody with enhanced ADCC (antibody-dependent cell-mediated cytotoxicity). GTC’s intellectual property includes a patent in the United States through 2021 for the production of any therapeutic protein in the milk of any transgenic mammal. GTC’s transgenic production platform is particularly well suited to enabling cost effective development of proteins that are difficult to express in traditional recombinant production systems as well as proteins that are required in large volumes. Additional information is available on the GTC web site, http://www.gtc-bio.com.