Filing under Rule 425 under the Securities
                                  Act of 1933 and deemed filed under Rule 14a-12
                                         of the Securities Exchange Act of 1934.
                                                          Filing by Genesys S.A.
                                             Subject Company: Vialog Corporation
                                               SEC File No. of VIALOG: 001-15527


[LOGO] GENESYS Conferencing                      [LOGO] VIALOG(R)
                                                        The Conferencing Company

                                 [LOGO] astound


          o    VIALOG SHAREHOLDERS APPROVE THE ACQUISITION OF VIALOG BY GENESYS.

          o    GENESYS SHAREHOLDERS APPROVE THE CAPITAL INCREASE RELATING TO THE
               VIALOG AND ASTOUND ACQUISITIONS.

          o    ASTOUND SHAREHOLDERS APPROVE THE ACQUISITION OF ASTOUND BY
               GENESYS.

MONTPELLIER, FRANCE - MARCH 23, 2001- Genesys S.A. (Euronext: 3955), Vialog
Corporation (Amex: VX) and Astound Incorporated today jointly announced that
Genesys shareholders have approved the capital increase required for the
acquisitions of Vialog and Astound. The companies also announced that Vialog
shareholders approved the acquisition of Vialog by Genesys at its March 23, 2001
shareholders meeting. Astound shareholders also approved the acquisition of
Astound by Genesys at its March 20, 2001 shareholders meeting.

ACQUISITION OF VIALOG

The merger agreement provides that Vialog shareholders will receive Genesys'
American Depositary Shares (ADSs) in exchange for their Vialog shares upon
closing. The exchange ratio will be determined on the basis of the
volume-weighted average share price of Genesys shares on Euronext-Paris for the
10 consecutive trading days ending on the second trading day prior to the day of
the closing. Under current market conditions, the exchange ratio will be fixed
at a maximum of 0.6703 ADSs for each Vialog share, resulting in Vialog
shareholders receiving approximately 24.8% of Genesys outstanding shares, after
giving effect to the Astound acquisition.

The ADSs will begin trading on the Nasdaq Stock Market under the symbol "GNSY"
after the closing.

Vialog's termination right remains unchanged, although, as previously announced,
Vialog's board re-affirmed its intention to proceed with the merger under
current market conditions. The Board of Genesys previously announced it has
decided, based on current conditions, not to exercise its right to adjust the
exchange ratio if the board of Vialog were to decide to exercise its right to
terminate the merger agreement.

Genesys and Vialog announced yesterday that they have received commitments from
a bank group for a U.S. $ 125 million senior credit facility that will permit
Vialog Corporation to refinance its outstanding debt following its acquisition
by Genesys. The terms provided by the term sheet signed with the banks should
enable the merged companies to generate approximately U.S. $ 4.5 million of
annual cash savings related to interest costs compared with Vialog `s current
interest costs. Availability of the credit facility is subject to due diligence,
documentation and other customary conditions for a facility of this kind.

Closing of the Vialog acquisition is expected to occur in conjunction with the
loan closing in approximately four weeks.



ACQUISITION OF ASTOUND

The Astound shareholders approved the acquisition of Astound by Genesys at their
meeting on March 20, 2001. The merger agreement provides that Astound
shareholders will receive exchangeable shares of Astound, exchangeable at their
option into an aggregate of 1,000,000 ordinary shares of Genesys and U.S. $7
million in cash at closing, and U.S. $ 3.55 million in cash on January 4, 2002,
together with interest thereon. The Genesys shares received by Astound
shareholders upon exchange of their exchangeable shares will be listed on
Euronext Paris. The merger closing is scheduled to occur before the end of
March.

Francois Legros, Chairman and Chief Executive Officer of Genesys, Kim Mayyasi,
Chief Executive Officer of Vialog and Kailash Ambwani, President of Astound
stated : "We are excited by our shareholders' strong support as demonstrated by
their vote to merge our businesses. This is a significant step in creating a
global powerhouse in the conferencing industry, with unique geographical
coverage and a strong customer base. Further, with the acquisition of Astound,
the Group's technological leadership will be enhanced within the fast growing
internet segment of our industry."

ABOUT GENESYS CONFERENCING:

Founded in 1986, Genesys Conferencing is one of the world's leading independent
conferencing specialists : audio conference, data conference, video conference
and webstreaming. Working in a rapidly growing market and enjoying unique
world-wide coverage as a result of its geographic expansion policy, Genesys
Conferencing has established its advanced technology in 16 countries throughout
Europe, Asia Pacific and the United States. Genesys Conferencing is listed on
the Nouveau Marche in Paris (Euroclear code: 3955).

ABOUT VIALOG:

Vialog is a leading provider of teleconferencing and messaging services,
including audioconferencing, videoconferencing, web conferencing, voicemail
broadcast, e-mail broadcast and fax broadcast. Vialog helps its more than 6,000
corporate customers communicate more professionally, efficiently and effectively
by delivering superior customer service and an extensive range of enhanced and
customized conferencing solutions. Vialog's common stock (symbol: VX) is quoted
on AMEX. For more information, visit Vialog.com for direct, online access to
Vialog's conferencing and messaging services.

ABOUT ASTOUND:

Founded in 1996 and based in Toronto, Astound is a leading provider of Web
conferencing and collaboration services, enabling companies to communicate in
real-time with customers, employees and partners. The Astound Conference Center
is a complete, integrated platform for one-to-one and small group collaboration
as well as large scale Web events. Astound has 100 employees and had sales for
the 12 months ended December 31, 2000 U.S. $ 2.5 million. Astound's services are
distributed via a direct sales force to customers such as Hewlett Packard,
Minolta, Lexmark, DLJ Direct, NCR and Teklogix.

AT GENESYS

                                                                      
  PIERRE SCHWICH                   MARINE BRUN                              FLORENCE CATEL
  EVP, Finance                     Shareholder and Investor Relations       Press Relations
  Tel: +33 4 67 06 27 55           Tel : + 33 4 67 06 75 17                 Tel : + 33 4 67 06 27 49
  Pierre.scwich@genesys.com        investor@genesys.com                     florence.catel@genesys.com



AT VIALOG

MIKE SAVAGE

Chief Financial Officer
Tel : 781-761-6200
Msavage@vialog.com



US SEC FILINGS

Genesys Conferencing has filed a Registration Statement on Form F-4 (No.
333-55392) with the United States Securities and Exchange Commission in
connection with the Vialog transaction. The Form F-4 contains a proxy
statement/prospectus relating to the Vialog special meeting and other related
documents. Vialog has mailed the proxy statement/prospectus contained in the
Form F-4 to its stockholders. The Form F-4 and proxy statement/prospectus
contains important information about Genesys, Vialog, the Vialog transaction and
related matters. Investors and stockholders should read the proxy
statement/prospectus and the other documents filed with the US SEC in connection
with the Vialog transaction carefully before they make any decision with respect
to the Vialog transaction. A copy of the merger agreement with respect to the
Vialog transaction has been filed by Vialog as an exhibit to its Form 8-K dated
October 2, 2000. The Form F-4, the proxy statement/prospectus, the Form 8-K and
all other documents filed with the US SEC in connection with the transaction are
available free of charge at the US SEC's web site at www.sec.gov. In addition,
the proxy statement/prospectus, the Form 8-K and all other documents filed with
the US SEC in connection with the Vialog transaction will be made available to
investors free of charge by calling or writing to:

Genesys S.A.
Pierre Schwich
Chief Financial Officer
4 Rue Jules Ferry, BP 1145
34008 Montpellier, Cedex 1, France
Phone: 33 4 67062755
email: pierre.schwich@genesys.com

Vialog Corporation
Michael E. Savage
Chief Financial Officer
32 Crosby Drive
Bedford, MA  01730
Phone: 781-761-6200
Email: msavage@vialog.com

In addition to the Form F-4, the proxy statement/prospectus and the other
documents filed with the US SEC in connection with the Vialog transaction,
Vialog is obligated to file annual, quarterly and special reports, proxy
statements and other information with the US SEC. You may read and copy any
reports, statements and other information filed with the US SEC at the US SEC's
public reference rooms at 450 Fifth Street, N.W., Washington, D.C. 20549 or at
the other public reference rooms in New York, New York and Chicago, Illinois.
Please call the US SEC at 1-800-SEC-0330 for further information on public
reference rooms. Filings with the US SEC also are available to the public from
commercial document-retrieval services and at the web site maintained by the US
SEC at http//www.sec.gov.

SOLICITATION OF PROXIES; INTERESTS OF CERTAIN PERSONS IN THE TRANSACTION

The identity of the people who, under SEC rules, may be considered "participants
in the solicitation" of Vialog stockholders in connection with the proposed
merger, and a description of their interests, is available in a SEC filing on
Schedule 14A made by Vialog on October 2, 2000.

FORWARD-LOOKING STATEMENTS

This 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 other than historical information or
statements of current condition. These statements appear in a number of places
in this release and include statements concerning the parties' intent, belief or
current expectations regarding future events, including: the growth of
Ready-to-Meet revenues, the anticipated timing of the Genesys Conferencing
transaction, and the benefits and results of the Genesys Conferencing
transaction. Forward-looking statements are not guarantees of future performance
and involve risks and uncertainties, and actual results may differ materially
from those in the forward-looking statements as a result of various factors.
Although management of the parties believe that their expectations reflected in
the forward looking statements are reasonable based on information currently
available to them, they cannot assure you that the expectations will prove to
have been correct. Accordingly, you should not place undue reliance on these
forward-looking statements. In any event, these statements speak only as of the
date of this release. The parties undertake no obligation to revise or update
any of them to reflect events or circumstances after the date of this release,
or to reflect new information or the occurrence of unanticipated events. Readers
are referred to Vialog's Annual Report to Stockholders and Genesys
Conferencing's and Vialog's other filings with the US SEC for a discussion of
these and other important risk factors concerning the parties and their
respective operations.