NEW YORK (AP) - If Timothy Geithner is confirmed as the country's next Treasury secretary, his supporting role in managing the country's fast-evolving financial crisis would be over. He would now take the lead.

As president of the Federal Reserve Bank of New York - often considered the second-most powerful position in the Fed system - Geithner has worked alongside Treasury Secretary Henry Paulson in marathon meetings aimed at bolstering failing financial institutions and fixing the country's clogged credit markets.

Some say that experience will be vital in enabling a seamless transition from one administration to the next, and Wall Street has been in a cheery mood since President-elect Barack Obama chose him for the job. The Dow Jones industrial average has climbed 892 points in the past two trading sessions, closing Monday at 8,443, and producing the Dow's biggest two-day percentage gain since October 1987.

Others are leery of having Geithner becoming the country's point man on fixing the worst financial crisis since the Great Depression. In particular, they worry that Geithner, 47, will merely continue Paulson's approach, which has been criticized as unfocused.

Regardless, Geithner has developed a reputation as a pragmatist when it comes to devising rescue plans for troubled banks.

Beginning in February, Geithner worked with JPMorgan Chase CEO Jamie Dimon to orchestrate its government-backed buyout of foundering Bear Stearns Cos. During the weekend in mid-September when the government allowed Lehman Brothers Holdings Inc. to collapse but decided to keep American International Group afloat, Geithner - along with Paulson - was in charge, leading discussions between scads of bank executives, regulators and lawyers.

Geithner is "not an ideologue," said Brian Gardner, a public policy analyst at investment bank Keefe, Bruyette & Woods.

But just how he might advise President-elect Barack Obama on issues other than the financial crisis are less well-known

"He doesn't have a lot of background or writings on tax policy," Gardner said.

Geithner (pronounced: GYT-ner) worked at Treasury for 13 years ending in 2001, having played a key role in shaping U.S. response to the Asian currency crisis of 1997 to 1998.

In Geithner's last job at Treasury, he was under secretary for international affairs under Secretaries Robert Rubin and Lawrence Summers.

Both Summers and Rubin served as outside advisers to the search committee that chose Geithner for the New York Fed job. Peter Peterson, co-founder of private equity firm Blackstone Group LP, led the committee and called Geithner "admirably equipped to confront the unique domestic and international challenges that will face our financial system over the coming years."

Summers was appointed Monday as director of the National Economic Council. Rubin is senior counselor at Citigroup Inc., the foundering financial supermarket that stands to get a $20 billion federal bailout.

While friends say Geithner's temperament is similar to Obama's - even-tempered - some critics say he tends to take disagreements as a personal challenge.

"I would expect his confirmation hearings to be animated, with some strong opposition asking questions about his involvement in the AIG, Lehman, Goldman, Morgan and Bear decisions by the New York Fed," said Joshua Rosner, managing director at research firm Graham Fisher & Co. in New York.

Geithner spent most of his childhood abroad, living in India, Thailand and Zimbabwe. His father, Peter Geithner, is an Asia expert who worked at the Ford Foundation for 28 years.

Geithner studied Chinese at Dartmouth, spending at least one summer in China.

After graduating in 1983, he earned a master's in international economics and East Asian Studies from Johns Hopkins School of Advanced International Studies, graduating in 1985.

Before joining Treasury, he worked for Kissinger Associates Inc., the consulting firm founded by former Secretary of State Henry Kissinger.

After leaving Treasury in 2001, he worked for the International Monetary Fund, where he was director of policy development. He's been president of the New York Fed since 2003.

Geithner met his wife, Carole Sonnenfeld Geithner, in his senior year at Dartmouth. The couple has two children.