D.C. Mayor Vincent C. Gray said Wednesday that he now supports building an aboveground Metrorail station at Dulles International Airport.

Gray’s position increases the political pressure on the board of the Metropolitan Washington Airports Authority, which is overseeing construction of the rail extension to Dulles and favors a more costly underground station that is closer to the terminal.

Gray (D) “reconsidered the position,” he said at a news conference, “because I don’t want to wind up with nothing.”

He said he was persuaded by discussions Tuesday with Virginia Gov. Robert F. McDonnell (R) and last week over lunch with former Virginia congressman Tom Davis, a member of the authority’s board. Both McDonnell and Davis have backed an aboveground airport stop.

Local, state and federal officials are pressing the airports authority to back away from the underground location and to reduce the cost of the second phase of the Metro project, now estimated at $3.5 billion. The board met behind closed doors for more than two hours Wednesday to consider a possible compromise brokered by U.S. Transportation Secretary Ray LaHood that would shave the cost to below $3 billion. A key element includes building an aboveground station to save at least $330 million.

Board Chairman Charles D. Snelling said after the meeting that “we are strongly considering and strongly receptive to LaHood’s proposal.” But Snelling stressed that the board had not reversed course. Any deal, he said, would require a heftier financial contribution from the state of Virginia and the federal government, in part to reduce future increases in toll rates for Dulles Toll Road users.

“The burden falls almost entirely on us, and there are others that should be stepping up to the plate,” he said.

Some members of the board are disappointed federal transportation officials have suggested that federal loans would be initially available to Fairfax and Loudoun counties — and not to the airports authority — to help pay for the project.

It was not immediately clear how Gray’s change of heart would affect the 13-person board, which includes members appointed by the president, the governors of Virginia and Maryland and the District mayor.

“It does have an impact,” said former D.C. Council member H.R. Crawford, one of three District members on the authority’s board. But he said: “At this juncture, I remain committed, if we can work it out, to the underground rail plan. There has to be some kind of consensus with our partners.”