ASSOCIATED PRESS WRITER

JAMES RUBIN

WASHINGTON (AP)—Airlines grudgingly agreed Wednesday to pay millions of dollars in additional fees for landing in Los Angeles in a deal that averts the threatened closing this weekend of one of America’s busiest airports.

The Clinton administration—which helped negotiate the settlement between the airlines and Los Angeles International Airport—promised to keep close tabs on increasingly strained relations nationwide between the airlines and airport managers.

Two days of arduous talks—called ‘‘shuttle diplomacy’‘ by the chief government mediator—were hailed by Transportation Secretary Federico Pena.

‘‘It’s a triple win’‘—for the traveling public, the airport and the airline industry, he said. ‘‘Today is a great day for the nation.’‘

But he warned the hard bargaining could foreshadow tough times ahead. Pena said he will announce a new policy next week spelling out the administration’s determination to ward off future crises as financially pressed airlines and cities battle over revenue.

The airlines, under protest, agreed to pay increased landing fees Los Angeles adopted July 1. The airlines will pay between $16 million and $18 million immediately, including retroactive increases to last July. The airport promised no further increases before next July.

The airlines will continue to press their case in federal court seeking to overturn the higher fees. A federal court hearing on an airline lawsuit opposing the fees has been scheduled for Monday.

The talks lasted more than 20 hours, including more than 14 hours on Tuesday to reach an agreement in principle and six more Wednesday to work out details.

Ted Stein, Los Angeles Airport Commission president, said ‘‘there are no winners or losers’‘ in the settlement. He credited Pena with ‘‘cajoling’‘ both parties into reaching an agreement.

James Landry, head of the Air Transport Association of America that represents major airlines, said that Pena’s promise that the administration will keep an eye on future developments is a key to the agreement.

Also, Landry said airlines are heartened by assurances from the administration of Los Angeles Mayor Richard Riordan that the increased airport revenues will not be diverted to non-airport uses.

Federal Aviation Administration chief David Hinson, the chief government negotiator in the bargaining, said he learned a lot about ‘‘shuttle diplomacy’‘ as he moved from room to room at the Transportation Department, carrying messages back and forth between both sides.

Los Angeles International Airport has nearly 2,000 takeoffs and landings a day.

Fees were more than tripled July 1 from 51 cents to $1.56 per 1,000 pounds. That means a Boeing 747 landing costs an airline about $900.

The airlines say the new fees are higher than needed to pay airport operating expenses. The city contends that fees under a recently expired, 40-year agreement were artificially low.

Earlier this month, U.S. Supreme Court Justice Sandra Day O’Connor denied a request by 40 airlines and the Air Transport Association for an emergency injunction barring the city from imposing the higher fees.