The nation's top transit official urged Virginia leaders to diminish their $4 billion dream of extending Metro to Dulles International Airport because it would cost too much and carry too few riders.

Instead, Federal Transit Administrator Jennifer L. Dorn told several Virginia Congress members and state and local officials to consider building rail only as far as Tysons Corner and running rapid bus service through the rest of the Dulles corridor, according to several people at the tense closed-door meeting.

"A lot of local and state officials felt as though somebody had doused them with cold water," said Rep. James P. Moran Jr. (D-Va.), adding that some seemed stunned, and that others appeared angry. "It was a dose of realism and a pretty bitterly cold dose."

The suggestion to scale back plans to build a 24-mile rail line to Dulles, envisioned since the 1950s, comes weeks after Northern Virginia voters refused to tax themselves to help pay for the project and as the state struggles to fill a $1 billion budget hole.

But even before the November election, the Bush administration had raised questions about the cost-effectiveness of the Dulles project, the third most expensive rail proposal in the country.

"We reinforced that federal funding was not a given, that there are important statutory criteria that need to be met in terms of cost-effectiveness, and we agreed to work together," Dorn said.

Others in Room 2358 of the Rayburn House Office Building said Dorn warned she was likely to reject the Dulles rail project because the predicted ridership of 71,900 daily trips did not justify the cost. She noted that rail would cost 10 times as much as a rapid bus system but carry only a little more than twice as many riders, according to a Metro analysis.

Dorn said that if the project was reduced to rail to Tysons Corner, at a cost of about $1 billion, that probably would win federal approval, according to those present.

Yesterday's meeting was the first joint gathering of federal transit officials, members of Congress, state and local politicians, airport officials and landowners, participants said. Rep. Frank R. Wolf (R-Va.) said he called the group together "because we wanted everyone to have the same information at the same time."

The meeting comes about two weeks before Virginia is scheduled to officially propose the rail project to the federal government and seek FTA approval to begin preliminary engineering. The state had been hoping to submit the plan in time for the reauthorization of the national transportation spending bill in 2003.

Virginia Transportation Secretary Whittington W. Clement said the state will follow Dorn's suggestion to break the project into segments, which would go to the FTA for analysis of costs and data to see whether they meet federal funding standards. He said the "logical" pieces would be from Falls Church west to Tysons Corner and from Tysons Corner west to Dulles.

Clement said he did not know what effect breaking the construction into segments would have on the overall timing of extending rail to Dulles. Early projections -- now considered unrealistic -- were that the line would be completed by about 2010.

"I think we all recognize that rail to Dulles is not going to be built as quickly as people have said in the past," Clement said. "It's going to take some time because of funding issues, but those aren't issues that are insurmountable."

Several people at the meeting said rail boosters, including former senator Charles S. Robb and Metro General Manager Richard A. White, challenged Dorn's assessment and argued vigorously for rail. Robb has been lobbying for the rail project on behalf of major landowners in the Tysons area. Others suggested that political support for any kind of transit in the Dulles corridor -- including rapid buses -- will disintegrate if rail is built only to Tysons.

An immediate hurdle to the Tysons plan is likely to be raised by the Metropolitan Washington Airports Authority, which owns the right of way needed for any rail project. James A. Wilding, president of the authority, has said in the past that the authority is determined to bring Metro to Dulles and won't allow rail to Tysons to be built without a guarantee that the line will be extended to the airport. Wilding said he got no such commitment yesterday. "Frankly, I'm sobered by the difficulty of it, but I walk away encouraged."

Leo J. Schefer, president of the Washington Airports Task Force, a group of businesses and citizens that support Dulles, said the ridership projections that the FTA analyzed were too low. He said limiting rail to Tysons Corner would leave out major employers in the Dulles and Route 28 corridors that generate about one-fourth of the region's economy. It also wouldn't serve the 60 percent of people who work in Tysons and commute there from the west, Schefer said.

After the meeting, the future of rail to Dulles seemed clouded, and state and local officials said the next step is uncertain.

"It will happen," Moran said of extending rail to Dulles. "I think my grandkids are going to be able to take rail all the way out to Dulles, but they're in grade school right now."

Staff writer Spencer S. Hsu contributed to this report.

Former senator Charles S. Robb has been lobbying for the project on behalf of landowners near Tysons.Rep. Frank R. Wolf called together federal, state and local leaders, landowners and airport officials.