Former Treasury Secretary Larry Summers on Sunday took his name out of the running to be the next chairman of the Federal Reserve.

“This is a complex moment in our national life,” Summers wrote in a letter to President Obama on Sunday. “I have reluctantly concluded that any possible confirmation process for me would be acrimonious and would not serve the interest of the Federal Reserve, the administration or, ultimately, the interests of the nation's ongoing economic recovery.”

Summers informed Obama of his decision by phone on Sunday, an administration official confirmed to the Washington Examiner.

"Earlier today, I spoke with Larry Summers and accepted his decision to withdraw his name from consideration for Chairman of the Federal Reserve," Obama said in a statement Sunday. "Larry was a critical member of my team as we faced down the worst economic crisis since the Great Depression, and it was in no small part because of his expertise, wisdom, and leadership that we wrestled the economy back to growth and made the kind of progress we are seeing today."

Summers, Obama's former chief economic adviser and Treasury Secretary under President Bill Clinton, was seen by many as the frontrunner for the job. Obama has gone out of his way to defend Summers, a rare move ahead of making an official nomination.

Federal Reserve Vice Chairwoman Janet Yellen, the preferred pick of many Democrats, is now seen as the likeliest choice by Obama.

The White House on Friday said Obama hasn't yet made a decision about the successor to Federal Reserve Chairman Ben Bernanke.