A press officer for the federal courts in San Francisco said Walker, 66, plans to return to the private sector, the Los Angeles Times reported Wednesday.
Walker was nominated as a judge by President Ronald Reagan and then again by President George H.W. Bush. His original nomination was stalled because he was perceived as anti-homosexual for representing the U.S. Olympic Committee in litigation against the "Gay Olympics," the Times said.
In August, he ruled that Proposition 8, the 2008 referendum banning same-sex marriage in California, is unconstitutional. The ruling is currently being appealed.
Walker has been chief judge of the federal court in San Francisco for the past six years. The press officer said his decision to leave is unrelated to the Proposition 8 suit and that details about his future plans may be released in coming weeks.