Los Angeles Mayor Antonio Villaraigosa on Thursday announced a settlement with three cities, the county and a neighborhood group that had sued to stop a massive overhaul of Los Angeles International Airport.

The agreement calls for Los Angeles officials to suspend major portions of the plan, including a controversial remote check-in facility, reduce the number of aircraft gates at the airport and provide an additional $240 million in soundproofing to nearby homes.

In exchange, the plaintiffs agreed to drop their lawsuit and allow work to proceed early next year on $1.2 billion in improvements to the south runway and the Tom Bradley International Terminal and the installation of explosives detectors at baggage screening sites.

“I am elated that at last we have the ability to move forward with a rational, community-sensitive plan for LAX that allows for sensible improvements for the people of Los Angeles. This will be a world-class airport for a world-class city,” Villaraigosa said at a press conference announcing the settlement.

Airport officials said Thursday that a revised modernization plan that includes surface traffic improvements around the airport and plans to upgrade Ontario and Palmdale Airports (also owned by the city) would be crafted over the next year. That plan will then take another 18 months to garner the necessary environmental approvals, meaning any additional work would not begin until late 2008.

The settlement was greeted with praise from a wide array of local elected officials at Thursday’s press conference, including El Segundo Mayor Kelly McDowell. “El Segundo has fought LAX and its plans for unconstrained growth for nearly 10 years now. Today’s breakthrough agreement constrains growth at LAX and helps jump-start a truly regional aviation plan.”

Villaraigosa campaigned against the $11 billion overhaul plan put forward three years ago by former L.A. Mayor James Hahn. That plan had come under intense fire from neighbors concerned it wouldn’t cap growth at the airport. It also drew criticism in a study by the Rand Corp. that said a remote passenger parking and check-in facility would actually increase the risk of casualties from a terrorist attack.

Villaraigosa also voted against a compromise crafted by former Councilwoman Cindy Miscikowski last year. The deal split off the most controversial elements of the plan for further study.

Shortly after taking office, Villaraigosa overhauled the Board of Airport Commissioners, replaced Los Angeles World Airports Executive Director Kim Day with former airport director Lydia Kennard and started settlement talks with the plaintiffs who had filed their lawsuit earlier this year.

The settlement announced Thursday must still be ratified by the Los Angeles City Council, the city councils of the three plaintiff cities, the Los Angeles County Board of Supervisors and the Federal Aviation Administration. Local approvals are expected swiftly, but FAA action may take longer because of the unprecedented reduction in the number of gates at one of the nation’s busiest airports.

That reduction, which would kick in once annual passenger count tops 75 million, would take the number of gates from 163 to 153. Airline representatives are expected to lobby fiercely against this reduction.

On Thursday, a spokesman for the Air Transport Association, which represents the major commercial air carriers, said airline officials had not gotten a detailed look at the settlement and were thus not in a position to comment.

Meanwhile, the most controversial and expensive elements of the Hahn plan the remote check-in facility at Manchester Square and the demolition of three northside terminals are effectively dead. Villaraigosa and airport officials said Thursday they would look at alternative ideas to reduce surface congestion. They also said they are awaiting the results of a second Rand Corp. study on security before coming up with alternatives; that study is due out early next year.

As part of the settlement announced Thursday, two elements of the Hahn-Miscikowski plan that were supposed to be fast-tracked construction of a consolidated car rental facility and a people-mover system to connect the Metro Rail Green Line to the airport are being set aside for further study. Airport officials insisted at Thursday’s press conference that those elements will still go forward, but only after the revised plan is presented and approved.