All but two stations in Metro's 103-mile rail system will be completed within the next 10 years as a result of an agreement reached Wednesday between the Bush administration and congressional negotiators, officials said yesterday.

The Senate approved the Metro legislation last night, and the House is expected to follow suit within a few days.

Administration officials, led by Transportation Secretary Samuel K. Skinner, have pledged that President Bush will not veto the bill, despite his initial wish to slash the federal government's share of the construction costs.

The reauthorization bill, if it becomes law, means that of the planned Metro system, first financed in 1965 by Congress and President Johnson, only 2 1/2 miles of the Green Line would remain to be financed and built, officials said.

With the $2.1 billion in federal and local money available under the agreement, the money would finance the long-awaited Green Line from U Street-Cardozo to Fort Totten, and from Anacostia to Naylor Road in Prince George's County, leaving only the stations at Suitland and Branch avenues unbuilt. Metro also would complete the Red Line's last station at Glenmont in Montgomery County and a station at Franconia-Springfield in Fairfax County.

At the same time, the agreement cuts the federal contribution from 80 percent to 62.5 percent. That change almost doubles the amount that financially strapped local governments now contribute, and some officials said a regional tax -- such as a gas or sales levy -- may someday have to be considered to operate the rail line.

Nevertheless, jubilant Metro officials and all of the region's members of Congress gathered on the Capitol lawn yesterday afternoon to celebrate their victory with hugs, kisses and a photo opportunity. Several said the agreement was extraordinary, given the federal budget crisis and the Bush and Reagan administrations' longstanding desire to sharply reduce federal money for Metro.

"They made us take a hit," said Rep. Steny H. Hoyer (D-Md.), referring to the reduced federal share of construction costs. "But we're on the brink of passing a bill which I think {many people} said wouldn't happen this year or ever."

A senior administration official also claimed victory, noting the sharp increase in local contributions. "We only signed up when the price was right," he said.

When the 103-mile system is complete, Metro estimates ridership will grow to 875,000 daily trips, and just over 1 million trips by the year 2010. About 513,000 trips are currently made each day on Metrorail.

Under the agreement, the federal government would provide $1.3 billion over the next eight years toward completing 11 of the remaining 13.5 miles. Local governments would kick in an additional $780 million over eight years, meaning there would be $2.1 billion available for construction. Another $700 million would be needed to finish the 2 1/2 miles of the Green Line.

For all the enthusiasm yesterday, the agreement would also mean that the two state governments and eight local governments that share in the cost of Metro construction would have to contribute substantially more money at a time when area governments already are strapped financially and are being asked to pay higher subsidies for Metro operations.

Right now, local governments pay 20 percent of the construction costs, about $51 million a year, or $415 million over the last eight years. Under the new plan, local governments would pay about $98 million a year, or $780 million over the next eight years.

On top of that, operating subsidies -- the difference between what Metro collects from fares and what it costs to run the system -- would double to $500 million a year in 10 years.

Higher subsidies also would force the region to consider how to finance local mass transportation, other than through higher fares.

"That always brings you to the question of whether or not ultimately there has to be a regional tax," said Metro General Manager Carmen E. Turner, who will leave the agency in December to become a top executive of the Smithsonian Institution.

Turner worked feverishly behind the scenes to assure the approval of a new Metro construction bill even before she contemplated leaving, so the agreement Wednesday was a personal triumph that did not go unnoticed.

"We're going to be less effective, I'm afraid, in the future without her leadership and energy," said Rep. Stan Parris (R-Va.).

How the agreement came together was a story not only of personal lobbying but of political considerations by the administration, several participants said.

"The key was the funding match," said Sen. John Heinz (R-Pa.), also a major player.

A few weeks ago, sources said, a deal was struck between Secretary Skinner and congressional negotiators that called for a federal share of 65 percent and a local share of 35 percent.

But Budget Director Richard G. Darman balked, insisting on a formula of 60 percent federal and 40 percent local.

The administration believes that local governments should pay more of the costs, as they do in other cities with transit systems.

The administration has also contended that Metro should compete with other transit systems for the estimated $400 million available nationwide for new transit construction, instead of having its own appropriation.

In the end, Hoyer said, the administration simply realized that it was fighting a losing battle because of Metro's bipartisan support in both houses.