WASHINGTON (AP) _ The Clinton administration lobbied successfully Tuesday to save the C-17 airlifter, a plane that carries as much political clout as military cargo.

In a 330-100 vote, the House authorized $2.5 billion for six of the huge aircraft next year, two more than the House Armed Services Committee recommended. The vote led Rep. Elizabeth Furse, D-Ore., to withdraw her amendment that would have terminated the troubled C-17 program after next year.

A letter from President Clinton to House Speaker Thomas Foley, D-Wash., that was circulating among lawmakers Tuesday defended the transport plane as ''crucial to the Air Force's ability to deliver and sustain forces'' in foreign battles.

Long Beach, Calif., where some 10,000 McDonnell Douglas Corp. workers assemble the C-17, is a key political concern for Clinton. In the 1992 election Clinton pulled California, the largest electoral prize, into the Democratic column for the first time since 1964 by adding support in Southern California to the party's traditional base in the north.

Critics noted the plane has more than doubled in price since it was begun. Administration analysts admit that McDonnell Douglas failed to meet minimum performance requirements for payload and range. Early versions of the plane were beset by faulty wings and by a cumbersome design system.

Rep. Ronald Dellums, D-Calif., a critic of the C-17, said that while Clinton lobbied hard, ''the administration did not answer for the record the concerns'' about the plane. And Rep. George ''Buddy'' Darden, D-Ga., said the C-17 was so expensive that commanders would be reluctant to send it into battle zones.

Supporters cited broad backing for the plane among top military officers and said that with so much invested to date, it would be a waste to kill the C-17.

The vote came as the House continued debate on a bill authorizing a $262.7 billion defense plan for next year. The Senate's defense bill is still in committee.

In a largely party-line vote, the House rejected, 221-191, a Republican proposal to limit financial support of U.N. peacekeeping operations.

Lawmakers also voted, 223-201, against a military invasion of Haiti and for a plan to use a Haitian island as a ''safe haven'' for refugees and a base for ousted President Jean-Bertrand Aristide. The amendment expresses congressional opinion and is non-binding.

In a 362-68 vote, the House refused to delay the 1995 base closure round until 1997.

Rep. James Hansen, R-Utah, proposed the amendment, saying the government was falling behind in cleaning up and selling off dozens of bases already shut down in previous base closure rounds. But the Clinton administration argued that a two-year delay would cost $9 billion and other lawmakers said Congress had to resist the temptation to delay difficult closure decisions.

The House also passed, 380-42, an $8.8 billion military construction authorization for base cleanup, closure and construction projects.

In his letter on the C-17, Clinton argued that the Pentagon is pressuring McDonnell Douglas, the prime contractor, to improve its performance. Cutting the number of aircraft, Clinton argued, would remove one of the incentives for McDonnell Douglas to improve.

The cut would also raise the price of each plane by as much as $50 million and ''cause at least 8,000 layoffs over the next two years,'' the president wrote.

Under the current Pentagon plan, the government would buy 12 more C-17s in the next two years for a total of 40 aircraft and a cost of $21.3 billion, or $534 million each. The amendment passed by the House would provide for six C- 17s next year and eight the following year.

The C-17 was designed to fly oversized military cargo such as M-1 tanks and Patriot missile batteries to remote battle zones under less-than-ideal landing conditions.

''The C-17 is the only aircraft that can meet these core military requirements,'' Clinton said.

Components of the C-17 are built by some 3,000 workers in St. Louis, home of House Majority Leader Richard Gephardt, D-Mo. Those C-17s already delivered to the Air Force are flown out of Charleston Air Force Base, S.C., home state of Sen. Strom Thurmond, senior Republican on the Senate Armed Services Committee.