President Barack Obama must nominate a new President of the World Bank soon, ahead of its annual meeting in Washington in June.

Last month, Robert Zoellick, 58, a Republican appointed by President George W. Bush in 2007, announced his retirement, opening the door to Obama. As the bank's biggest shareholder, the U.S. has always held the presidency of the World Bank, much like its financial flows counterpart, the International Monetary Fund, has been headed by someone from Europe.

France's Christine Lagarde last year succeeded France's Dominique Strauss-Kahn as IMF director.

On Wednesday, developing countries said they'd push for a non-American candidate, putting forward two distinguished nominees: Nigerian Finance Minister Ngozi Okonjo-Iweala and former Columbian Finance Minister Jose Antonio Ocampo.

Okonjo-Iweala, 57, had served as World Bank VP and a managing director and would be the first woman World Bank president. Ocampo, 59, had been Undersecretary General of the United Nations for Economic and Social Affairs.

While the two non-U.S. candidates have some support, they would need to gather support from a near-unanimous anti-U.S. coalition at the World Bank's board. Japan, is the No. 2 member by votes, followed by China.

That could mean a candidate such as Singapore Finance Minister Tharman Shanmugaratnam, 55 Chinese Finance Minister Xie Xuren, 64, or Brazil Finance Minister Guido Mantega, 63, might be acceptable. Over time, it's expected China will become the world's largest economy.

Meanwhile, the White House has said Obama has narrowed down a list and plans to nominate someone shortly.

Non-starters, so far, are Secretary of State Hillary Clinton, 64, who has publicly ruled herself out, along with Secretary of the Treasury Timothy Geithner, 50, who wants to leave Washington soon.

In another era, a prominent banker might be a good pick. Previous World Bank presidents include James Wolfensohn, who came from Wall Street, and A.W. Clausen, CEO of the Bank of America (NYSE: BAC) . So Obama-friendly bankers such as James Dimon of JPMorgan Chase (NYSE: JPM) or Roger Altman of Evercore (NYSE: EVR) are probably out of luck.

Bankers are not popular now.

Former Treasury secretary Lawrence Summers, 57,  a former Obama adviser, who said "issues of intrinsic aptitude" keep women out of science when he was president of Harvard, might be a difficult pick.

Other potential candidates could include:

Sen. John Kerry (D-Mass.), the 2004 Democratic candidate for President. Kerry, 68, has long wanted a seat on the global stage and now serves as Chairman of the Senate Foreign Relations Committee. If he were selected, Gov. Deval Patrick would pick a Democratic successor for his seat.

Christina Romer, 53, professor of economics at the University of California, Berkeley, where she returned following service as Chairperson of the Council of Economic Advisers in Obama's first year.

Romer would be the first woman World Bank chief as well as the first academic.

Michael Bloomberg. The New York mayor, 70, might eye this as a cap to his career after becoming a billionaire on Wall Street via his Bloomberg LP information company, then service as three-term Mayor of New York.

The New York Times this month said Bloomberg had lunch with Obama, 50, during which the president asked him what he wanted to do next. His reply isn't known.

Bloomberg, whose term expires in 2013, has said he wants to spend his next period doing foundation work but presumably could be enticed to run the World Bank. A Democrat-turned-Republican-turned-independent, Bloomberg might be an appealing choice for Obama, although he's hardly been known as having an interest in poverty and development, spending much of his political capital on education.

Richard Levin, 64, President of Yale, is the only economist currently heading an Ivy League institution. Among the Big 10, Morton Schapiro, 58, President of Northwestern University and a distinguished economist, might be a candidate.

The World Bank president now earns a salary of $441,980 plus $284,500 in other benefits. The bank lent $57 billion in its last fiscal year.