(Adds details of alleged scheme, no immediate comment from Pomponi's lawyer, background)
WASHINGTON, July 17 (Reuters) - A former vice president of Alstom SA's U.S. unit pleaded guilty on Thursday over his role in a scheme to bribe Indonesian government officials to win a $118 million power project there, the U.S. Department of Justice said.
William Pomponi, a former vice president of sales for the French company's Connecticut-based power subsidiary, pleaded guilty to conspiring to violate the Foreign Corrupt Practices Act.
The case centered on a $118 million contract to provide services at a power plant in Sumatra. The contract, known as the Tarahan project and completed in 2007, was part of a joint venture between Alstom and Japan's Marubeni Corp.
Pomponi's plea adds further pressure on Alstom, which is also under investigation by U.S. prosecutors and potentially faces hundreds of millions of dollars in fines for violating a U.S. law that bars bribes to officials of foreign governments.
The plea comes one month after the French turbine and train maker agreed to a controversial $16.9 billion deal with General Electric under which the U.S. conglomerate will acquire most of Alstom's energy business.
Two other executives who worked at Alstom, including a former vice president of global boiler sales and a vice president of regional sales at the U.S. unit, have already pleaded guilty in connection with the scheme.
Marubeni pleaded guilty in March to participating in the seven-year scheme and was ordered to pay an $88 million criminal fine.
A lawyer for Pomponi and a U.S. lawyer for Alstom did not immediately respond to requests for comment.
Prosecutors accused the former Alstom executives of bribing an Indonesian lawmaker and members of the state-owned electricity company to get their help in securing the contract.
They concealed the bribes through payments to two purported consultants, prosecutors said.
(Reporting by Aruna Viswanatha; Editing by Chris Reese and Cynthia Osterman)