Filed by Sanofi-Synthelabo
                                  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: August 9, 2004


     On August 9, 2004, Sanofi-Synthelabo issued the following press release.

     In connection with the proposed  acquisition of Aventis,  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-Synthelabo  ordinary
shares   (including    Sanofi-Synthelabo    ordinary   shares   represented   by
Sanofi-Synthelabo  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~SYNTHELABO LOGO]

[GRAPHIC] Investor Relations

                      SANOFI-SYNTHELABO'S OFFER FOR AVENTIS
                        PROVISIONAL RESULTS OF THE OFFERS

PARIS,  FRANCE -- AUGUST 9, 2004 --  Sanofi-Synthelabo  (PARIS:  SAN, NYSE: SNY)
announces that the French Autorite des marches  financiers (AMF) today published
the provisional results of its offers for Aventis.  These results indicate that,
as of the expiration of the offers, in aggregate  769,920,773 Aventis shares had
been tendered  into the French,  German and U.S.  offers,  including the Aventis
shares  underlying  ADSs  tendered  into the U.S.  offer.  In  addition,  92,692
warrants  issued by Aventis in 2002 and  164,556  warrants  issued by Aventis in
2003 were tendered into the French offer.

These results indicate that 769,920,773  Aventis shares  representing  95.47% of
the share capital and 95.52% of the voting  rights of Aventis,  on an issued and
outstanding  basis as of July 31, 2004, have been tendered into the offers. On a
fully-diluted basis, Aventis shares representing 89.84% of the share capital and
89.88% of the voting rights of Aventis have been tendered.  If these provisional
results are confirmed by the AMF in its notice of the  definitive  results,  the
minimum tender condition will be satisfied and  Sanofi-Synthelabo's  offers will
be successful.

Sanofi-Synthelabo  expects that the AMF will announce the definitive  results of
the offers on August  12,  2004.  These  definitive  results  will  include  the
definitive results of the mix-and-match  elections and any necessary  allocation
and  proration  as a  result  of the  oversubscription  of  either  the all cash
election or the all stock election.

Sanofi-Synthelabo  expects that the settlement of the offers and the delivery of
the offer  consideration  in respect of tendered  Aventis  ordinary  shares will
occur on Friday,  August 20, 2004 and in respect of Aventis ADSs tendered in the
U.S. offer no later than  Thursday,  August 26, 2004 (to allow for the necessary
foreign exchange conversions).

Assuming the definitive results confirm these provisional results, as previously
disclosed,  Sanofi-Synthelabo intends to provide a subsequent offering period of
at least 10 French trading days. Sanofi-Synthelabo expects to publish the timing
of the subsequent offering period on or about August 12, 2004, after it has been
set by the AMF.




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 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
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")  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, Gruneburgweg 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-Synthelabo,  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-Synthelabo  ordinary  shares  (including
Sanofi-Synthelabo  ordinary shares represented by Sanofi-Synthelabo ADSs) in the
United  States will only be made  pursuant  to a  prospectus  and related  offer
materials  that  Sanofi-Synthelabo   expects  to  send  to  holders  of  Aventis
securities. The Sanofi-Synthelabo  ordinary shares (including  Sanofi-Synthelabo
ordinary shares represented by Sanofi-Synthelabo  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-Synthelabo'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-Synthelabo, 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  Autorite des Marches  Financiers  on
April 2,  2004,  could  cause  actual  results to differ  materially  from those
described in the forward-looking statements: the ability of Sanofi-Synthelabo to
expand  its  presence   profitably  in  the  United   States;   the  success  of
Sanofi-Synthelabo's   research  and   development   programs;   the  ability  of
Sanofi-Synthelabo  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-Synthelabo  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 (No.  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.



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