by Charles V. Bagli

Reeling from the real estate downturn in the city, construction unions and builders are edging closer to an agreement that they say will reduce labor costs and enable at least some of their projects in Manhattan to proceed despite the weak economy.

The stakes are high for both sides. Developers, who paid record-breaking prices for land during the boom years, are now desperately seeking ways to cut their costs and keep projects alive.

The unions, in turn, are eager to keep their members employed and to retain their traditional dominance over large-scale projects in New York. Yet many are reluctant to give up hard-won wages and benefits.

Some construction managers and union officials involved in the negotiations say that the pending agreement on work rules, wages and benefits would cut labor costs by 15 to 20 percent, but not the 25 percent originally sought by builders. Many involved are loath to discuss it publicly for fear of blowing up the fragile talks with the union construction trades, all of which are covered by contracts. The carpenters and the electricians have been much more willing to bend, union officials and contractors say, than the steamfitters and the operating engineers, the highly paid operators of cranes, bulldozers and other heavy equipment.

Some developers, however, are skeptical that any agreement will translate into substantial savings. Some doubt whether even a 25 percent reduction would be enough to salvage a residential project when rents have dropped by a third or more.

“A lot of my developers are concerned that it doesn’t go far enough,” Steven Spinola, president of the Real Estate Board of New York, said of the proposed agreement. “But we’re grateful discussions are taking place.”

Among the developers pushing for a deal are Larry Silverstein, who is building at ground zero, Stephen M. Ross, who has a slow-moving project on 42nd Street at 10th Avenue, and the Milstein family, which has a project under way at Battery Park City.

The three people at the center of the negotiations — Raymond G. McGuire, president of the Contractors Association of New York, Louis J. Coletti, president of the Building Trades Employers Association, and Gary La Barbera, president of the Building and Construction Trades Council of Greater New York, an alliance of unions — did not return calls requesting comment.

“Industry leaders,” said James A. Parrott, chief economist at the union-supported Fiscal Policy Institute, “should be seeking help from Washington to retain construction jobs and maintain wages, benefits and safety standards.”

“Our national economic recovery depends on labor and management working together to expand and not weaken the middle class,” he said.

Construction employment in New York City climbed to roughly 130,000 during the boom years. But a report by the New York Building Congress predicts that that number could fall by 23 percent to 100,000 next year.

Nonunion projects are showing up in what has been a union bastion: Manhattan. The Atlantic Development Group is putting up an 89-unit apartment house at 10th Avenue and 23rd Street in Chelsea with nonunion contractors. And at a union job on the Upper West Side, the Chetrit Group and Stellar Management took the highly unusual step of asking contractors for new bids on three 15-story buildings already under construction on Columbus Avenue, between 97th and 100th Streets. Developers and union officials expect nonunion contractors to take over the project.

“Our main goal was to continue with the project and keep as many people working as possible,” said Jeff Gdanski, a vice president at the Chetrit Group.

Bruce Ratner, a developer who traditionally builds with union contractors, recently stopped at the 38th floor of his planned 76-story Beekman Tower in Lower Manhattan, threatening to cap the building at 40 stories if construction unions did not accept concessions on wages and work rules.

Mr. Ratner, who is not involved in the current negotiations, stopped work for three months early last year while he scrambled to obtain $680 million in construction financing. At that time, he decided to switch from condominiums to rentals. In another cost-cutting move, he modified the design by the architect Frank Gehry, using a standard curtain wall instead of one that would seem to be undulating, on one of the tower’s eight sides.

It was not so long ago that major Manhattan developers and their lenders worried little about these things, figuring that rents and sale prices would gallop well ahead of the surging cost of land, concrete and steel.

But the cityscape is now littered with half-finished towers that have run into financial problems. Construction managers say that developers are stuck with land costs of $400 a square foot or more, up from $200 five years ago.

In January, developers and construction managers who often use union contractors began talking about a citywide agreement on wages, work rules and benefits. Developers and managers say they prefer union contractors, despite their higher wages, because they provide highly skilled workers.

“This year is not too bad,” said one union official who insisted on anonymity because he was not supposed to discuss the talks. “But 2010 is looking like we’re going off the ledge.”

But many unions have balked at wage cuts, particularly those who have not suffered layoffs, like cement workers and operating engineers. Some contractors have also questioned the value of the concessions that some unions have agreed upon, even ones that have been verified by consultants. There was talk of a compromise for a select group of six projects, including those owned by Mr. Ross, Mr. Silverstein and the Milstein family.

Executives and labor officials who have been briefed on the latest discussions say the unions may agree to consider projects on a “case-by-case” basis for a special “project labor agreement” that would save developers whose projects are otherwise not viable up to 20 percent on the current labor contracts.