The head of President Obama's Auto Task Force has decided to step down from that position, the Treasury Department announced Monday.

Steve Rattner, a financier and investor who was tapped to lead the administration's efforts to restructure General Motors and Chrysler, "has decided to transition back to private life and his family in New York City," Treasury Secretary Tim Geithner said in a statement.

Rattner's tenure as head of the Presidential Task Force on the Auto Industry saw the Obama administration initially reject restructuring plans of GM and Chrysler and demand the resignation of GM's then-CEO, Rick Wagoner, before both of the automakers were eased into a prestructured bankruptcy in late spring.

Ron Bloom, a former top official for the United Steel Workers who had been serving as Rattner's principal co-chair of the task force, will now assume leadership of the task force, the Treasury said.

Rattner's decision to return to private life comes after GM emerged from bankruptcy last week to complete the months-long restructuring of the company.

"We are extremely grateful to Steve for his efforts in helping to strengthen GM and Chrysler, recapitalize GMAC, and support the American auto industry," Geithner said in a statement announcing Rattner's departure. "I hope that he takes another opportunity to bring his unique skills to government service in the future."

"There is still much work ahead to ensure that GM and Chrysler re-emerge as stronger, more competitive companies. President Obama has made it perfectly clear that it is the responsibility of their private boards of directors and management teams to deliver that result," Geithner added. "And thanks to the hard work of Steve, Ron, and the entire Auto Task Force, they have a much better chance today of rebuilding those companies and making them once again symbols of American success."