US financial watchdogs have uprated their investigation into accounting practices at Vivendi into a formal probe, the French media giant has said.

Vivendi said it would co-operate fully with the formal investigation by the Securities and Exchange Commission.

The announcement comes two weeks after the company admitted it was the subject of a preliminary SEC investigation.

The SEC has declined to comment.

Difficult times

The announcement comes at a sensitive time for Vivendi, which is attempting to reinvent itself from the media-to-waterworks giant created by former chairman Jean-Marie Messier.

The already faces a probe by the Office of the United States Attorney for the Southern District of New York.

And, since July, the company has also been under investigation by French stock exchange regulator Comission des Operations de Bourse (COB).

The investigation is into Vivendi Universal's financial accounts since January 2001.

Yet, under the leadership of Jean-Rene Fourtou, Vivendi has sought to spin-off non-core holdings, including its stake in Vivendi Environnement, and fend off an attempt by Vodafone to seize control of French telecoms firm Cegetel.

Vivendi owns 44% of Cegetel.