Factbox: Likely candidates to replace Bernanke at Fed in 2014

Lawrence Summers, a former top economic aide to President Barack Obama and a Treasury secretary under President Bill Clinton, withdrew his name from consideration to succeed Ben Bernanke as Federal Reserve chairman on Sunday.

Widely regarded as a brilliant economist and a shrewd and decisive policy-maker, Summers was considered to be the front-runner to replace Bernanke, whose second term expires in January.

The former White House advisor was widely viewed as Obama's top choice, but he had generated unusually fierce opposition from progressive groups. He was criticized for his track record on financial deregulation and for remarks made about women that were criticized as sexist.

Summers' decision to drop out appears to make Fed Vice Chair Janet Yellen a strong contender for the job. But Obama has been careful to say he is considering other candidates as well to take the helm of the Fed.

Here is a quick look at the likely leading choices:

JANET YELLEN (Born August 13, 1946)

Yellen, 67, has been Fed vice chair since 2010 and is viewed as a strong contender to be the next Fed chair.

A Reuters poll in June 12 found that an overwhelming majority of economists predicted she would get the job. But her chances appeared to slip recently after Summers' friends launched an aggressive lobbying campaign on his behalf.

Yellen has been a forceful advocate of the aggressive steps taken under Bernanke to spur U.S. economic growth, earning her a reputation as a policy "dove" who would tolerate a bit more inflation to drive down unemployment that she deemed too high.

If picked to succeed Bernanke, she would become the 100-year-old central bank's first female chief. Before her current post, Yellen was president of the Federal Reserve Bank of San Francisco. She was chairman of the White House Council of Economics Advisers under President Bill Clinton and a Fed Board governor in Washington from 1994 to 1997.

A former professor at the University of California, Berkeley, Yellen has high standing among other academics. She began her career as an assistant professor at Harvard University in the early 1970s before shifting over to the Fed.

DONALD KOHN (Born November 7, 1942)

Kohn, who retired as Fed vice chair in 2010 after 40 years at the central bank, is a respected economist who would be viewed as a very safe pair of hands at the Fed, if he could be persuaded to return to public office.

Obama publicly named him as one of the candidates he is considering.

People who have worked with Kohn have the utmost respect for his ability and think he would make an excellent choice, but they wonder if he really wants to take on such a grueling job.

Before taking a Fed board seat, Kohn, 70, was a top staff lieutenant to then-Chairman Alan Greenspan. He is now an external member of the Bank of England's Financial Policy Committee, which sets broad guidelines for the British financial system, and a senior fellow at the Brookings Institution, a Washington think tank.

TIMOTHY GEITHNER (Born August 18, 1961)

Timothy Geithner, 52, was Obama's first-term Treasury secretary. He is also seen as a possible contender for the Fed nomination, but has said he does not want the job.

If Geithner could be persuaded to change his mind, his track record is compelling. Before he was tapped for Treasury, he was already at the center of the nation's emergency response to the financial crisis as head of the New York Fed.

He also held senior posts in the Clinton Treasury Department and at the International Monetary Fund, and has longstanding contacts with the nation's largest banks. However, some critics view those ties to Wall Street as an impediment and say he was not tough enough on the banks, which contributed to excessive risk-taking that ultimately led to the 2007-2009 housing crisis.

Geithner had a difficult Senate confirmation as Treasury secretary in 2009 after it surfaced that he had failed to pay some taxes, and that issue might re-emerge if he is tapped for the Fed. Some lawmakers called for Geithner's resignation early in his tenure at Treasury, but many Republicans later warmed to him, seeing him as an honest broker during tough budget talks.

ROGER FERGUSON (Born October 28, 1951)

Ferguson, 61, is chief executive officer of TIAA-CREF, which manages retirement funds for many U.S. schools and hospitals. A Harvard-educated economist and lawyer who was Fed vice chairman from 1999 to 2006, Ferguson was regarded within the Fed as a smart and thorough policymaker. His appointment would be groundbreaking: He would be the first African-American to chair the U.S. central bank.

(Reporting By Alister Bull; Editing by Stacey Joyce)