In the latest sign of the growing coordination among social groups and the sway they are having on development projects, the city of Los Angeles has agreed to pay nearly $500 million to provide environmental mitigation and jobs-related benefits programs to the neighborhoods affected by plans to upgrade and expand the Los Angeles International Airport.

As expected, the Los Angeles City Council yesterday approved the agreement struck between the Los Angeles World Airports, the city department that owns and operates the Los Angeles International Airport and three other airports in Southern California, and a 22-member coalition of environmental, neighborhood, labor, social and religious groups and two school districts.

The legally-binding accord includes measures to soundproof schools and homes in the airport area, set up opportunities for businesses and residents in the impacted area to get aviation and airport-related work, study the impact of the airport's operations on the health of nearby residents, and boost funding to reduce airport noise, emissions and traffic. The Los Angeles World Airports will fund the measures outlined in the agreement. In return, the coalition has promised not to sue the city over its $11 billion plan to upgrade and expand the airport.

"It was in our best interest to negotiate rather than litigate," says Daniel Tabor, one of the lead negotiators of the agreement and a resident of Inglewood, Calif., one of the cities affected by operations at the airport. "The coalition gave standing and a seat at the table for people who for years have been complaining about the negative impacts of the airport and have opposed past airport-expansion plans," he says.

The airport accord is the latest in a growing number of so-called community-benefits agreements. The concept was pioneered in Los Angeles by the nonprofit Los Angeles Alliance for a New Economy to allow local residents and groups to have a say in shaping a major development project, press for benefits from the project and mitigate its harmful effects. The concessions typically are granted in exchange for pledges from the groups that are parties to the agreement not to file lawsuits or otherwise stand in the way of the development proceeding. Efforts to hammer out such agreements between residents and developers or public agencies are underway from New York to Seattle.

In New York, a group of neighborhood, civic and business leaders are pressing Columbia University to help create low-income housing in the West Harlem area where the university has proposed to expand. In Seattle, a public-interest coalition is negotiating with city officials and representatives of Vulcan Inc., billionaire Paul Allen's company, which is seeking to develop an area north of downtown into a biotechnology hub, to address affordable-housing, transportation, job and environmental issues.

At least a dozen such agreements are in the works in the U.S., according to Madeline Janis-Aparicio, executive director of Los Angeles Alliance for a New Economy (LAANE). "It's a relatively new movement to reshape the nature of land use and economic development," she says. "It's at its most advanced stage in Los Angeles because that's where we came up with it."

The key to working out community-benefit agreements, "is keeping communities, residents and organizations informed to be able to participate in a serious way in the process," says Ms. Janis-Aparicio. "They need to understand how decisions are made, how land use and economic development works in the area, and they need to know about these projects in advance. Once the shovels hit the ground, it's too late."

So far, LAANE has been involved with negotiating community-benefits agreements stemming from about half a dozen development projects. In 2001, the nonprofit was part of a coalition of 25 community groups and five unions that reached a $70 million agreement with the developer of a four-million-square-foot expansion of the Staples Center in downtown Los Angeles, which included plans to develop two hotels, shops, restaurants, housing and expand the Los Angeles Convention Center.

At the time, many residents in the area felt they had been left out of the planning process when the Staples Center arena was built in 1999. Seeking a role in the expansion plan, the coalition groups banded together and negotiated an agreement with the Los Angeles Arena Land Co., a company owned by Philip Anschutz and Rupert Murdoch, to give local residents first shot at jobs created by the project, guarantee that 70% of the jobs created by the project pay a living wage of $10.04 an hour without health benefits and $8.79 with benefits, and provide $1 million for a park, among other things.

Most of the $500 million allocated by the Los Angeles airport accord will go toward noise abatement and job training. The accord requires the Los Angeles World Airports to spend $15 million over a five-year period on training residents of Inglewood and Lennox and other communities affected by the airport upgrade-and-expansion plan for aviation- and airport-related jobs. Residents will also be given the first shot at airport jobs. The Inglewood and Lennox school districts will receive $229 million over 10 years to soundproof schools, most of which have simply boarded up classroom windows to suppress the noise from airplanes taking off and landing. A little more than $43 million over a five-year period will go to soundproofing homes in the affected areas.

"None of the organizations in the coalition are getting money from this agreement," says Jerilyn López Mendoza, policy director of the Los Angeles office of Environmental Defense, a New York-based nonprofit that is a member of the coalition. "The money is going directly to the mitigation programs and job programs."

Los Angeles World Airports will pay for these measures through bonds, reserves, concessions and parking revenues, passenger charges, airline landing fees and terminal rents, according to an agency spokesman. The agreement must still pass muster with the Federal Aviation Administration, since the city is seeking to use airport revenues to fund the measures.

"We feel very good about the agreement," says Jim Ritchie, deputy executive director of long-range planning at the Los Angeles World Airports, who was involved with negotiations on the agreement. He says the FAA was briefed on the agreement, which was "well received," although the FAA gave no formal indication of whether it will approve the agreement. "Here we were," says Mr. Ritchie, "a team of airport personnel and typical opponents coming together with an approach, rather than waiting for litigation and the same groups appearing in court."

Ms. Muto is a national real-estate writer for The Wall Street Journal. Her "Bricks & Mortar" column appears most Wednesdays exclusively on RealEstateJournal. She is based in the Journal's San Francisco bureau.