NEW YORK/WASHINGTON Sept 29 (Reuters) - Long-time U.S. Department of Justice official Daniel Kahn, who oversaw high-profile bribery cases against French energy company Alstom SA and Brazilian construction conglomerate Odebrecht SA, is leaving government for the private sector, a source told Reuters. Kahn will join white-shoe defense firm Davis Polk & Wardwell, said the source, who was familiar with the move. Kahn and spokespersons for the Justice Department and Davis Polk did not immediately reply to requests for comment. The U.S. Senate confirmed Kenneth Polite to lead the Justice Department"s criminal division in July, but Polite has yet to make permanent picks to lead the division"s fraud section, which spearheads the agency"s criminal enforcement against corporations and their executives.Last year, the fraud section secured $2.9 billion in U.S. criminal penalties and payments, and settled several high-profile cases including a market manipulation probe against JPMorgan Chase & Co (JPM.N) and foreign bribery charges against Goldman Sachs Group Inc (GS.N) for its role in Malaysia’s 1MDB corruption scandal. The companies admitted wrongdoing as part of the settlements. As acting deputy assistant attorney general in the criminal division, Kahn led the criminal division"s fraud and appellate sections. Before that, he had various leadership roles within the fraud section, including three years overseeing the team that handles foreign bribery cases. He joined the Justice Department in 2010 after working six years at Davis Polk. The cases against Alstom (ALSO.PA) in 2014 and Odebrecht in 2016 both resulted in corporate guilty pleas and what were record fines at the time.