Christopher Steskal, the federal prosecutor who indicted the country’s first stock option backdating prosecution in July -and the leader of a criminal probe into Apple Inc.’s options grants � will leave the San Francisco U.S. attorney’s office next month to lead the white-collar practice at Fenwick & West.

Steskal has been busy with options prosecutions in recent weeks � Apple CEO Steve Jobs was interviewed by prosecutors and SEC lawyers earlier this week, according to people familiar with the case. But the offer from Fenwick was too enticing, Steskal said.