Los Angeles' airport agency is prepared to spend upward of $100 million under a groundbreaking agreement that would ensure neighborhoods most harmed by LAX operations receive specific benefits from airport modernization, officials said Wednesday.

The legally binding Community Benefits Agreement would be the first of its kind in the nation linked to a public works project and could set a precedent for other cities to follow, according to representatives from the coalition that is negotiating the pact with Los Angeles World Airports, which operates LAX.

The agreement would provide Lennox, Inglewood and southwest Los Angeles with benefits that could include soundproofing, new and accelerated environmental and health programs and local hiring guarantees.

Airport agency officials estimate the programs will cost from tens of millions to hundreds of millions of dollars, said Jim Ritchie, LAWA's deputy executive director of long- range planning and the airport agency's negotiator.

"The communities that are the most impacted are, in fact, the poorest communities, the most minority communities, and receive fewer benefits from airport business," said Bruce McDaniel, superintendent of the Lennox School District, which sits directly under arrival routes used by hundreds of low-flying planes a day. "They should receive benefits to mitigate the fact that the airport creates problems to their daily lives."

The proposed agreement, however, could face opposition from the airline industry, which would end up funding the programs through airplane ticket taxes.

"Community support is important, but this proposal strikes me as a little off-center," said Doug Wills, vice president of communications for the Air Transport Association, a powerful national airline lobbying group.

"In general, U.S. airlines would oppose any ... measures that would transfer federal tax dollars dedicated for airports away from actual airport improvements."

A group of school districts, labor unions and community and environmental organizations -- which calls itself the LAX Coalition for Economic, Environmental & Educational Justice -- has been negotiating the pact with the airport agency for the past three months.

Negotiators hope to ship an agreement to the Board of Airport Commissioners in August for approval, said Maria Loya, policy director for the Los Angeles Alliance for a New Economy, which is one of the coalition members.

Mayor James Hahn urged airport officials to negotiate with the coalition, said Phil Depoian, an LAX deputy director who also serves as Hahn's airport liaison.

The city's airport and planning commissions this week approved a compromise version of Hahn's $9 billion LAX modernization plan.

Numerous possible mitigation measures are included in the plan's environmental impact report.

But the proposed benefits agreement would require specific measures favored by local communities, said Jerilyn Lopez Mendoza, policy director of the Environmental Justice Project, the Los Angeles arm of the national Environmental Defense organization.

"That's basically our interest -- not just ensuring that any mitigations happen but that they are the ones the community decides is important," Mendoza said.

Community benefit agreements have been reached in recent years on several privately funded developments in Los Angeles, including the downtown Staples Center.

And the city of New York passed a law requiring that clean-burning construction equipment be used during the rebuilding of the World Trade Center complex, Mendoza said.

But Mendoza and Loya said they believe the proposed agreement over LAX modernization would be the first such pact on a public works project.

"L.A.'s been setting the tone for the rest of the country," Mendoza said.

The scope of the LAX modernization agreement, however, will be limited by federal regulations requiring that airport-generated revenue be spent on airport-related projects.

The Federal Aviation Administration rejected a proposal that LAX pay for tutors for children whose learning has been harmed by aircraft noise, McDaniel said.

But airport and coalition representatives said separately that they're committed to seeing how far they can stretch federal rules.

"We're going to push the envelope and explore areas that maybe in the past were closed to us," said Ritchie, who directed the development of LAX modernization plans pushed by Hahn and his predecessor, Richard Riordan.

For example, the airport may try to win federal approval to better soundproof Lennox schools that it previously paid to soundproof two decades ago, Ritchie said.

Other projects could include:

• Accelerated retrofitting of airplane gates so that aircraft waiting to be loaded and unloaded can be powered electrically rather than having to run their engines, which spews pollution into the air.

• Quicker conversion of ground support equipment to natural gas.

• A consolidated shuttle system for airport-area parking lots and hotels.

• A study to determine which airborne toxins are due directly to airport operations.

• Local hiring opportunities and ongoing living wage jobs.