WASHINGTON — President Barack Obama’s second term is likely to have some different faces in key economic positions, starting with a new Treasury secretary to replace departing Timothy F. Geithner.

Securities and Exchange Commission Chairwoman Mary Schapiro also reportedly is considering stepping down, a year before her five-year term ends in early 2014. And Federal Reserve Chairman Ben S. Bernanke might not want to re-up for another four-year term as head of the central bank.

Geithner has stated clearly that he would not stay if Obama was re-elected. In fact, he was close to stepping down after the bitter 2011 negotiations with Congress over increasing the nation’s debt ceiling, but Obama persuaded him to stay through the end of his first term.

“I’ve had a lot of excitement in my job, more than my share,” Geithner said in September when asked whether the improving economic recovery would encourage him to remain at his post. “But I think the president … should have a chance, and will have a chance, to have somebody excellent and capable come in and help him with those challenges.”

It’s rare for Cabinet secretaries to serve more than four years. And Geithner took the job in 2009 after dealing with the financial crisis through 2008 as president of the Federal Reserve Bank of New York.

It’s unclear when Geithner would depart. White House and Treasury officials declined to comment Wednesday.

Obama’s first term technically doesn’t end until Jan. 20. And it’s highly unlikely Geithner would leave before then because he would be a key player in the Obama administration’s negotiations with Congress over avoiding the “fiscal cliff” of large tax increases and government spending cuts coming at the start of next year.

Analysts have been speculating for months on possible Geithner replacements.

The names most frequently mentioned are White House Chief of Staff Jacob Lew and former Clinton White House Chief of Staff Erskine Bowles.

Bowles co-chaired the National Commission on Fiscal Responsibility and Reform, dubbed the Simpson-Bowles commission after him and his Republican co-chair Alan Simpson, which proposed a widely praised comprehensive deficit reduction plan last year.

Speculation also has swirled that Schapiro will step down soon, with a report in September saying she was considering resigning. Democratic Commissioner Elisse Walter has been mentioned as a possible replacement.

And there are several names being floated for the job of Fed chairman should Bernanke not want to go through another potentially tough confirmation fight. The New York Times reported last month that Bernanke had told friends he would not seek another term even if Obama won. Republican presidential candidate Mitt Romney had vowed not to reappoint Bernanke if he won the presidency.

Former Obama economic advisor Lawrence Summers, who stepped down at the end of 2011, is a possible replacement, as well as Alan Krueger, who head Obama’s Council of Economic Advisors, and Fed Vice Chair Janet Yellin.