Closing date of Sanofi-Synthelabo's offer on Aventis postponed to July 30, 2004.

Closing date of Sanofi-Synthelabo's offer on Aventis postponed to July 30, 2004. Paris, June 22, 2004 In order to accommodate the timeframe necessary to receive the required approval from the United States Federal Trade Commission, the "Autorité des Marchés Financiers" has determined to postpone the closing date of Sanofi-Synthelabo's offer on Aventis to July 30, 2004. Sanofi-Synthelabo believes that the required approval will be in place prior to the revised closing date and the required divestitures will be consistent with the expectations announced by Sanofi-Synthelabo on January 26, 2004 when it launched the offer for Aventis. In accordance with article 7 of the COB rule no. 2002-04, this press release was transmitted to the Autorité des marchés financiers (AMF) before its publication. Important Information: In connection with the proposed acquisition of Aventis, Sanofi-Synthélabo 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 are being 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 complémentaire), which has been granted visa number 04-384 by the Autorité des marchés financiers ("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 réponse) which has been granted visa number 04-510. The public offer to holders of Aventis ordinary shares located in Germany (the "German Offer") is being 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, Grüneburgweg 14, D-60322 Frankfurt am Main (Fax: 069 - 152 05 277) and on the website of the Company (www.sanofi-synthelabo.com). Any decision to tender Aventis ordinary shares in exchange for Sanofi-Synthélabo ordinary shares under the German Offer must be taken exclusively with regard to the terms and conditions of the German Offer, as well as with regard to the information included in the offer document/sales prospectus, including any amendments thereto, issued in Germany. 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. It is intended that the three offers will expire at the same time. 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-Synthélabo with the SEC at www.sec.gov as well as of the Reference Document filed with the AMF on April 2, 2004 (N° 04-0391) at www.amf-france.org or directly from Sanofi-Synthélabo on our web site at: www.sanofi-synthelabo.com. ------------------------------------------------------------ Informasjonen er sendt gjennom Waymaker http://www.waymaker.no Nedenstående filer kan lastes ned: http://www.waymaker.net/bitonline/2004/06/23/20040623BIT20110/wkr0001.pdf