President-elect Barack Obama confirmed Monday the membership of his economic team, announcing Tim Geithner will serve as Treasury secretary while former Treasury Secretary Larry Summers will become director of the White House National Economic Council.

Obama, who spoke during a news conference in Chicago, also said economist Christina Romer will chair the White House Council of Economic Advisers and Melody Barnes will steer the White House Domestic Policy Council. Barnes is executive vice president for policy at the Center for American Progress and a former aide to Sen. Edward Kennedy (D-Mass.)

Obama shed little new light on his plans for the economy. But he indicated that the outlines of an economic stimulus proposal will be ready within weeks and said Congress should get busy legislating one when it returns early in January.

Obama confirmed that he still plans to end President George W. Bush’s tax cuts affecting those earning more than $250,000 per year, but he suggested he has not decided whether to repeal it or wait and let it expire.

He said he will make a new announcement Tuesday on plans to “reform how business is done in Washington,” including the budget process.

During Obama’s appearance, which included his new economic team members, the stock market dropped about 100 points but remained in positive territory.