If confirmed by the Senate, the 57-year-old Mr. Lew — Mr. Obama’s current chief of staff and former budget director — would become the president’s second Treasury secretary, succeeding Timothy F. Geithner, who was the last remaining principal from the original economic team that took office at the height of the global crisis in January 2009.
While the team is changing, so far it is made up entirely of men who have been part of the administration since its first months. Gene B. Sperling, like Mr. Lew a veteran of the Clinton administration, is expected to remain as director of the White House National Economic Council. Alan B. Krueger, a former Treasury economist, continues as chairman of the Council of Economic Advisers and Jeffrey D. Zients, a former business executive, as acting director of the Office of Management and Budget.
That composition gives Mr. Obama a high degree of comfort with his economic advisers, who have experience in the budget struggles that have occupied the administration since Republicans took control of the House two years ago. Those struggles will resume later this month. Yet the continuity also plays into criticism that the president is too insular and insufficiently open to outside voices and fresh eyes in the White House.
Adding to a scarcity of female advisers among Mr. Obama’s top aides, Hilda L. Solis, the secretary of labor for four years, announced on Wednesday that she would be resigning, following the most prominent female Cabinet member, Secretary of State Hillary Rodham Clinton, out of the administration.
Separately, administration officials let it be known on Wednesday that several Cabinet members will remain in their jobs: Kathleen Sebelius, the secretary of health and human services, who is expected to stay through the full adoption of the 2010 health care law in 2014; Eric H. Holder Jr., the attorney general; and Eric K. Shinseki, the secretary of veterans affairs.
If Mr. Lew is confirmed in time, his first test as Treasury secretary could come as soon as next month, when the administration and Congressional Republicans are expected to face off over increasing the nation’s debt ceiling, which is the legal limit on the amount that the government can borrow. Mr. Obama has said he will not negotiate over raising that limit, which was often lifted routinely in the past, but Republican leaders have said they will refuse to support an increase unless he agrees to an equal amount of spending cuts, particularly to entitlement programs like Medicare and Social Security.
Mr. Lew was passed over for Mr. Obama’s economic team four years ago, when Mr. Obama instead chose Lawrence H. Summers, a former Harvard University president and Treasury secretary, as director of the National Economic Council. Mrs. Clinton then hired Mr. Lew at the State Department, and in late 2010 — over the objections of Mrs. Clinton, who had come to rely on Mr. Lew — Mr. Obama made him budget director, the same post Mr. Lew had held late in the Clinton administration.
Mr. Lew in the 1980s was a Democratic adviser to the House speaker then, Thomas P. O’Neill, participating in fiscal talks with the Reagan administration. Mr. Lew is known for his low-key style and organizational skills.
While Mr. Lew has much less experience than Mr. Geithner in international economics and financial markets, he would come to the job with far more expertise in fiscal policy than Mr. Geithner did. That shift in skills reflects the changed times, when emphasis has shifted from a global financial crisis to the budget fights with Republicans in Congress.
The partisan tension suggests that Mr. Lew will be questioned closely by Senate Republicans in confirmation hearings.
But, Republicans have not signaled the kind of opposition they put up to some of Mr. Obama’s other potential nominations.
Mr. Lew’s departure as chief of staff would create a vacancy for what would be Mr. Obama’s fifth White House chief of staff, a turnover rate that is in contrast with the stability atop Treasury the last four years with Mr. Geithner. The leading candidates are said to be Denis McDonough, currently the deputy national security adviser in the White House, and Ronald A. Klain, a former chief of staff to two vice presidents, Joseph R. Biden Jr. and Al Gore.
Before joining the Obama administration, Mr. Lew spent a brief period in the financial sector, at Citigroup, first as managing director of Citi Global Wealth Management and then as chief operating officer of Citigroup Alternative Investments.
By contrast, Mr. Geithner had been president of the New York Federal Reserve Bank, which includes overseeing Wall Street. For the financial industry, Mr. Lew is a largely a blank slate.
“While he can undoubtedly learn the material on the job, we question whether he has sufficient relationships with the banking industry in the U.S. and abroad, which can be critical during a financial crisis,” Brian Gardner, head of Washington research for the investment banking firm Keefe, Bruyette & Woods, wrote to clients on Wednesday.
But Michael Schein, who worked with Mr. Lew at Citigroup and is now head of a nonprofit financial services organization, Accion, countered: “People in the business community like to deal with people in Washington who they can trust. I think Jack already does, and will do, very well with Wall Street and with business leaders because he is a very, very straight shooter.”
Mr. Lew has a reputation as a fiscal progressive who, like Mr. Obama, is eager to protect Medicaid and other antipoverty programs from deep cuts. But advocates for tighter financial regulation of Wall Street question whether he is too conservative.
The question is relevant because major regulations under the 2010 Dodd-Frank law remain to be put into effect in Mr. Obama’s second term.
“He appears to share a Wall Street mentality, particularly when it comes to financial reform,” said Dennis M. Kelleher, the president of Better Markets, a Washington-based nonprofit. “Financial reform is all about making the banking system safer and preventing more taxpayer bailouts.”
Annie Lowrey contributed reporting.
