SANOFI-SYNTHELABO'S OFFER FOR AVENTIS - TENDER PERIOD HAS EXPIRED

SANOFI-SYNTHELABO'S OFFER FOR AVENTIS - TENDER PERIOD HAS EXPIRED Paris, France - July 31, 2004 - Sanofi-Synthelabo (PARIS: SAN, NYSE: SNY) announces that the tender period for its French, German and U.S. Offers for Aventis expired simultaneously yesterday (July 30, 2004) at 23:00 hr (Central European Summer Time) and 5:00 p.m. (Eastern Daylight Time). Accordingly, holders of Aventis ordinary shares and ADSs may no longer tender into the offers and may not withdraw Aventis ordinary shares and ADSs that have already been tendered. Sanofi-Synthelabo expects that the French Autorité des marchés financiers (AMF) will publish the definitive results of the offers on August 12, 2004. Sanofi-Synthelabo also expects that, if the minimum tender condition has been met, the AMF will publish provisional results prior to publishing the definitive results. Sanofi-Synthelabo will issue a press release regarding the results of the offers promptly after each announcement by the AMF. In accordance with the requirements of the New York Stock Exchange, Sanofi-Synthelabo announces that as of 5:00 p.m. on July 30, 2004 (Eastern Daylight Time), a total of 25,131,998 Aventis ADSs had been tendered in and not withdrawn from the U.S. offer, including 1,741,137 Aventis ADSs subject to the guaranteed delivery period. Based on data provided by Aventis, these tenders represents approximately 92.9% of the Aventis ADSs outstanding and approximately 3.2% of Aventis share capital, in each case as of July 29, 2004 and on an issued and outstanding basis. These results are not final and will be combined with the overall results obtained in the French, German and U.S. offers. Because of French centralization procedures, the number of Aventis ordinary shares tendered in and not withdrawn from the offers cannot be known at this time and will be announced by the AMF as described above. 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-Synthelabo 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 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-Synthelabo 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. 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-Synthélabo, 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 solicitation of offers to buy Sanofi-Synthélabo ordinary shares (including Sanofi-Synthélabo ordinary shares represented by Sanofi-Synthélabo ADSs) in the United States will only be made pursuant to a prospectus and related offer materials that Sanofi-Synthélabo expects to send to holders of Aventis securities. The Sanofi-Synthélabo ordinary shares (including Sanofi-Synthélabo ordinary shares represented by Sanofi-Synthélabo 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 statements that constitute forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. 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-Synthélabo's management believes that the expectations reflected in such forward-looking statements are reasonable, investors 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-Synthélabo, 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. The following factors, among other risks and uncertainties that are described in our Form 20-F as filed with the SEC on April 2, 2004 and in the Reference Document filed with the French Autorité des Marchés Financiers on April 2, 2004, could cause actual results to differ materially from those described in the forward-looking statements: the ability of Sanofi-Synthélabo to expand its presence profitably in the United States; the success of Sanofi-Synthélabo's research and development programs; the ability of Sanofi-Synthélabo to protect its intellectual property rights; and the risks associated with reimbursement of health care costs and pricing reforms, particularly in the United States and Europe. Other than as required by applicable law, Sanofi-Synthélabo does not undertake any obligation to provide updates or to revise any forward-looking 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-Synthelabo with the SEC at www.sec.gov and may obtain the Reference Document filed with the AMF on April 2, 2004 (N° 04-0391) and other documents filed with the AMF at www.amf-france.org. Free copies may also be obtained directly from Sanofi-Synthelabo 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/2004/08/02/20040802BIT20120/wkr0001.doc http://www.waymaker.net/bitonline/2004/08/02/20040802BIT20120/wkr0002.doc http://www.waymaker.net/bitonline/2004/08/02/20040802BIT20120/wkr0004.pdf http://www.waymaker.net/bitonline/2004/08/02/20040802BIT20120/wkr0005.pdf