EXHIBIT 99(a)(5)(ix)

March 17, 2000

Elyo: Acquisition of Trigen Energy Corporation

BIDDERS ANNOUNCE AMENDMENT OF TENDER OFFER MATERIALS FOR SHARES OF TRIGEN

WHITE PLAINS, N.Y. and NANTERRE, France, March 17 /PRNewswire/ -- Trigen
Energy Corporation (NYSE: TGN) and ELYO, an energy subsidiary of the Suez
Lyonnaise des Eaux Group, jointly announced today that, in response to
comments made by the staff of the Securities and Exchange Commission, they
have supplemented certain disclosures made in connection with the
previously announced offer by T Acquisition Corp., an indirect, wholly
owned subsidiary of ELYO, to purchase any and all of the outstanding shares
of Trigen that ELYO does not already own for $23.50 a share in cash. All
terms of the tender offer remain unchanged from those disclosed in the
tender offer materials that were mailed to Trigen's shareholders on
February 28, 2000. The supplemental information has been filed with the
Securities and Exchange Commission, and is available to any Trigen
shareholder, free of charge, by contacting the Information Agent, Morrow &
Co., Inc. at (800) 566-9061.

Trigen is a leading developer, owner and operator of industrial,
commercial and institutional district energy and combined heat and power
(CHP) systems in North America. The company serves more than 1,500
customers with energy produced at 49 plants in 20 states, Canada and
Mexico.

CONTACT: Susan Odiseos, Director of Corporate Communications of Trigen
Energy Corporation, 914-286-6628; or Gilles Alligner, Director of
Communications of ELYO, +1-33-1-41-20-1293; or Jeffrey Zack of Morgen Walke
Associates, Inc, 212-850-5643.