D.C. Council Chairman Linda W. Cropp has set a vote on a plan to build a baseball stadium with public funds for Nov. 30, three weeks later than initially scheduled but with a slim majority still supporting the proposal.

Cropp's aides reiterated yesterday that she is leaning toward voting to approve the current legislation if an amendment is added that gives the council until June to explore private financing options.

Cropp's support would give Mayor Anthony A. Williams's plan a more solid majority. Seven of the 12 other council members were prepared to vote for the plan at a meeting last week, but Cropp (D) pulled the baseball bill from the agenda because she wanted more time to consider other financing ideas.

A spokesman for Williams (D) said the mayor supports adding the amendment Cropp is seeking.

"We continue to say we have been open to talking about the financing," spokesman Chris Bender said. "We're writing something for her review. The language is being worked out now."

In a pact with Major League Baseball, Williams agreed to fund the stadium in Southeast Washington through a combination of a gross receipts tax on large businesses, a tax on concessions and an annual rent payment by the team. In exchange, the Expos would be relocated from Montreal to Washington in the spring.

Baseball has given Washington until Dec. 31 to approve the stadium deal. The council would take a second and final vote on the legislation Dec. 14, Cropp's aides said.

Jack Evans (D-Ward 2), the council's most ardent stadium booster, said he would support an amendment that establishes a formal process to consider private financing options.

The council could examine the financing plans until June, when the first bond payment is expected to be due, city officials said.

But Evans stressed that "two weeks is an eternity in politics." And yesterday, one supporter of the mayor's plans expressed new concerns. Jim Graham (D-Ward 1) said his support is wavering because of the rising potential costs. The stadium, estimated by mayoral advisers at $440 million, could cost as much as $584 million if infrastructure is added, according to D.C. Auditor Deborah K. Nichols. A Washington Post analysis put the cost at $614 million.

Graham said he does not believe that the infrastructure costs would lead to such high overruns. But he said he feared that money for a community investment fund Williams has promised to create would be diverted if the stadium costs increased even modestly.

Graham has received a promise that $2 million of the gross receipts tax revenue each year would go toward debt service on $45 million in bonds for libraries. Graham said he wants to make sure the promise is set clearly in the legislation before voting to approve it.

Mayoral aides said the library amendment is still on track.

David A. Catania (I-At Large), who opposes using public funds for the stadium, said he intends to reintroduce several amendments he offered during a council session this month, such as ensuring that stadium workers earn a living wage and that a majority of construction jobs go to city residents.

The delay on the council's vote has forced the D.C. Sports and Entertainment Commission to hold back on renovating Robert F. Kennedy Memorial Stadium, where the baseball team would play for the next three years.

Commission officials have issued a request for construction bids and developed a list of companies that can do specific work on the stadium, Bender said. They are also in the process of hiring a project manager, he added. Commission officials did not return phone messages yesterday afternoon.

Natwar M. Gandhi, the city's chief financial officer, has said the delays already have raised projected costs of renovating RFK Stadium. The mayor's staff estimated the work to cost $13 million, but Gandhi's analysis put the figure at $24 million, largely because of projected overtime costs of workers rushing to meet the deadline.

Bender said the council's delay will not create significant problems in getting RFK ready for the opening home game April 15 against the Arizona Diamondbacks.