President Obama nominates current vice chair Janet Yellen as new head of Federal Reserve

If she replaces Ben Bernanke, Ms Yellen would be the first woman to lead the American central bank

President Obama is preparing to nominate Janet Yellen, the current vice chair at the Federal Reserve, to be the next head of the American central bank, ending months of speculation about the identity of Ben Bernanke's successor when he steps down from his post early next year.

Ms Yellen, who, if her nomination is confirmed by the US Senate, would be the first woman to lead the Fed, has been Mr Bernanke's deputy since 2010. Widely respected in both policy-making circles and among academic economists, she will inherit the country's top central banking job at a crucial juncture for the Fed, as it considers how and when to begin winding down the extraordinary stimulus measures put in place to support the US economy in recent years.

The President is expected to name her as his choice for the influential post on this afternoon, marking an end to an unusually controversial nomination process for the job.

During the summer, the White House was widely believed to be weighing the possibility of nominating Larry Summers, a former US Treasury Secretary under President Clinton and one-time adviser to President Obama.

Although Mr Summers also boasts strong academic credentials, his record as a cheerleader for financial de-regulation - he was front and centre during the Clinton administration's push to deregulate the financial sector - provoked the opposition of many within the President's own party.

His candidacy was also marred by memories of the controversy surrounding his resignation from the presidency of Harvard University in 2006. Mr Summers stepped down after seeming to suggest that men outperformed women in certain subjects owning to biological differences, remarks for which he soon apologised.

Last month, with signs that key Democratic Senators would oppose his candidacy, he eventually withdrew his name, citing the prospect of a bad-tempered confirmation battle in Washington and paving the way for Ms Yellen's nomination.