Washington, Jan 07 (Agencies): Overhauling his team at the top, President Barack Obama on Thursday named banker and seasoned political fighter William Daley as his new chief of staff, hoping to rejuvenate both a White House storming into re-election mode and an economy still gasping for help.

The choice of Daley immediately brought howls of protest from the left flank of the Democratic Party, where advocates questioned his insider ties to Wall Street.

Centrists, business leaders and Republican lawmakers rallied around the move, one that underscored just how much and how fast the face of the White House is changing.

"I'm convinced that he'll help us in our mission of growing our economy," an upbeat Obama said in a White House ceremony as Daley stood to one side.

On the other side of the president was Pete Rouse, the interim chief of staff who oversaw a busy three months but did not want to stay in the job.

Said Daley to his new boss: "This team will not let you down, nor the nation."

Rouse, who disdains the spotlight but is considered one of Obama's most essential advisers, choked back some rare public emotion as his colleagues gave him a rousing ovation and the president praised him. He will remain on board for the rest of Obama's current term as counselor to the president, the only one in the building to hold that elevated title.

As the new Republican majority in the House exerts its power, Obama has been resetting his team briskly, with one eye on governing and the other on getting re-elected. After two long years on the job, on top of two nonstop years of campaigning, some of Obama's most senior advisers are heading out.

The president is losing his press secretary, Robert Gibbs, and his trusted strategist, David Axelrod; he is bringing in former campaign chief David Plouffe as a top staff adviser starting Monday. Yet change only goes so far, as all three of them will end up playing vital roles in Obama's 2012 election campaign, just as they did last time.

On Friday, Obama is expected to name Gene Sperling as his chief economic adviser, who once served for President Bill Clinton — just like Daley.