WASHINGTON (CNN) - As President Barack Obama mulls whether to nominate Lawrence Summers to lead the Federal Reserve, the Harvard professor has suspended his activities with banking behemoth Citigroup.
"Mr. Summers has withdrawn from participation in all Citi events while he is under consideration to be Chairman of the Federal Reserve," Danielle Romero-Apsilos, a spokeswoman for the company, said in an e-mailed statement.
Oft-discussed as the president's preferred choice to succeed Ben Bernanke, Summers was set to keynote a Citigroup research seminar on October 13, according to an invitation on the website for the firm, the third-largest U.S. lender.
Romero-Apsilos confirmed an earlier Bloomberg News report that the former top economic adviser for the Obama White House is no longer scheduled to deliver that address. The report indicates that Summers, 58, is not advising the company on global and domestic economic issues.
While Obama has told legislators that Summers and Fed Vice Chairman Janet Yellen are potential candidates to take over the central bank, sources told CNN's Brianna Keilar earlier this week that the president has not made a decision about who to nominate.
Summers, if nominated, would face a difficult confirmation process. Despite Democrats holding a two-vote majority on the 22-member Senate Banking Committee, several Democrats on the panel have already voiced opposition to a Summers nomination.
Summers served as Treasury secretary under President Bill Clinton and backed deregulating the banking industry. Critics say the action was a major factor that led to 2007's financial collapse, from which the economy is still trying to recover.
Sen. Jon Tester became the latest Democratic member to raise concerns about Summers heading the Fed, announced he intends to vote "no" were the professor to be nominated.
"Senator Tester plans to vote against him in committee," Andrea Helling, a spokeswoman for the Montana Democrat, told Reuters.
Senators Elizabeth Warren, Jeff Merkley and Sherrod Brown have also expressed reservations about Summers assuming the critical financial post.
Bernanke's term as Fed chairman expires Jan. 31.