July 13 (Bloomberg) -- Steven Rattner, the Wall Street executive who helped the government guide General Motors Co. and Chrysler Group LLC out of bankruptcy, is stepping down, the Treasury Department said.

Ron Bloom, a former United Steelworkers union adviser and Lazard Ltd. vice president, will take over the leadership role in advising the Obama administration’s auto task force, the statement said. Bloom is currently an adviser to the task force.

Rattner is departing three days after the new GM formed with majority federal ownership, and in the month following the creation of Chrysler under government guidance. Rattner was named in February to help lead the federal process.

“What the task force did was an amazing feat in the time frame,” said Dennis Virag, president of the Automotive Consulting Group Inc. in Ann Arbor, Michigan. “His job was to take them in and out of bankruptcy as quickly as possible. He accomplished that job.”

Rattner, co-founder of private-equity firm Quadrangle Group LLC, helped form GM from bankruptcy ahead of the 60-to-90 days the government had estimated. Detroit-based GM filed for bankruptcy on June 1 after losing almost $88 billion since the end of 2004.

The auto adviser “has decided to transition back to private life and his family in New York City,” Treasury Secretary Timothy Geithner said in a statement. “I hope that he takes another opportunity to bring his unique skills to government service in the future.”

No Quadrangle Return

Rattner has no plans to return to Quadrangle, according to a person familiar with his plans. Quadrangle named Joshua Steiner and Michael Huber to run the firm after Rattner said he’d leave for the Treasury post.

President Barack Obama expressed confidence in Rattner in April after Quadrangle was linked to federal and state probes of millions of dollars in pension fund kickbacks. Rattner told Treasury before Obama took office about the investigation of alleged kickbacks made to intermediaries for a New York pension fund, a Treasury department spokesperson, who declined to be identified, said in April.

Robert Gibbs, Obama’s press secretary, told reporters on April 17 that Rattner wasn’t accused of doing any wrongdoing.

Demanding Concessions

Rattner and the task force helped push through the reorganizations of the automakers by demanding concessions from the companies, the United Auto Workers and bondholders. The panel rejected a recovery plan filed by GM in February and later ousted GM Chief Executive Officer Rick Wagoner.

Some groups, including creditors and some lawmakers, objected to the handing of the bankruptcy. Bondholders protested the asset sales of the companies as unfair, and a House panel voted last week to require GM and Chrysler to restore agreements with auto dealerships shed during bankruptcy proceedings.

GM has said it’s closing about 1,350 dealers to save costs. Chrysler Group didn’t keep 789 of 3,188 dealerships when it bought assets from bankrupt Chrysler LLC.

Rattner, along with Lazard executives Peter Ezersky, Steiner and David Tanner, started Quadrangle in 2000 after sketching out their plans in meetings at Rattner’s apartment on New York’s Fifth Avenue.

Quadrangle oversees about $6 billion in assets, mostly in media and communications investments. The firm also handles the personal and philanthropic finances of Michael Bloomberg, the founder and majority owner of Bloomberg LP, the parent company of Bloomberg News.

To contact the reporters on this story: To contact the reporters on this story: John Hughes in Washington at jhughes5@bloomberg.netRobert Schmidt in Washington at rschmidt5@bloomberg.net.

Last Updated: July 13, 2009 18:55 EDT