By PATRICK McGEEHAN

The owners of more than 3,200 apartment buildings in New York City reached an agreement on a new labor contract with the union that represents about 30,000 doormen, porters, janitors and building superintendents, averting a strike that was due to begin at 7 a.m. Wednesday.

The talks went right to the wire, as they often have in the past, with the union resisting the owners’ demands for cuts in health care and other benefits. In the end, the owners agreed to a new four-year contract that includes a total pay increase of nearly 10 percent and no significant cuts in benefits for the workers, an official with the union, Local 32BJ of the Service Employees International Union, said at 12:20 a.m. Wednesday.

Representatives of the owners had negotiated with union officials for several days leading up to the expiration of a four-year contract. The main points of contention had been the owners’ demand that the workers share some of the cost of their medical and dental benefits.

A strike would have disrupted the daily routines of hundreds of thousands of middle-class residents from upper Broadway to Brownsville, as well as affluent owners of Park Avenue penthouses. Along with picket lines in front of many of their homes, they would be confronted with the loss of the people who sign for their packages, carry their luggage and let the pizza deliverers and dog walkers into the building. Residents of many buildings have been asked to volunteer to pitch in to sort the mail, announce visitors by intercom, operate elevators and haul garbage to the curb if necessary.

Representatives of the workers and owners met on and off for several days at the Sheraton New York Hotel in Midtown.

A picketing plan that had been drawn up on Tuesday afternoon called for the workers to walk out at the end of the 11 p.m.-to-7 a.m. shift and begin picketing immediately outside selected buildings.

In 1991, they picketed for 12 days before reaching a compromise that gave them annual raises that averaged about 4 percent.

During that strike, city sanitation workers refused to cross the picket lines to collect garbage, leaving it to pile up on sidewalks until the health department declared it a public health nuisance and ordered that it be picked up. Along with the festering trash, residents of thousands of buildings had to contend with restrictions on deliveries and service calls by repairmen during the strike. They also had to perform chores that the doormen and porters usually handled, like sorting mail, operating elevators and carrying luggage.

New Yorkers who had to cope with that strike said they hoped not to have to endure another. Some said they and their neighbors were willing to try to handle duties themselves, but they had little confidence in their abilities to keep things running smoothly.

In the hours before the strike deadline, others were dreading a disruption in the don’t-do-it-yourself lifestyle of calling the super and ordering in Chinese that is particular to urban apartment dwellers.

“It would definitely be a big inconvenience,” said Nicole Auerbach, 36, who lives on West End Avenue. “Our doormen told me probably 50 percent of the people in our building have takeout delivered on any given night.”

In an effort to head off another walkout, the negotiations began in earnest on Thursday, with less than a week left on a four-year contract. That agreement had not been cobbled together until the wee hours after the previous one ran out at midnight on April 20, 2006.

The two sides met on and off through the weekend and all day Monday, breaking off at midnight. They resumed talking at 9 a.m. Tuesday.

The 30,000 union members were represented by about 60 people, led by Mike Fishman. The owners had a committee of about a dozen, led by Howard Rothschild, president of the Realty Advisory Board on Labor Relations.

The main points of contention in the talks were quite similar to the sticking points in the negotiations four years ago: The owners demanded that the workers shoulder part of the cost of their health care, and the two sides disagreed about what would be a fair pay raise for the next few years. In the end, the owners agreed to a contract that raised wages a little more than 8 percent over four years and did not shift any of the health care burden onto the workers.

On average, the union’s members earn about $40,000, or about $20 an hour, a union spokesman said. They also receive medical and dental care for themselves and their families, as well as 10 paid sick days, vacation and pensions. The owners estimated the total annual cost of employing a member of the union at more than $68,000.

This time, the owners argued that the recession that began more than two years ago had crimped their ability to be as generous. They cited “skyrocketing” property taxes and utility costs as reasons for demanding concessions on benefits.

Mary Ann Rothman, executive director of the Council of New York Cooperatives and Condominiums, said that for a growing number of tenants, raising the rent was not an option to cover increased labor.

“In co-ops and condos, we are the owners,” Ms. Rothman said. “There’s no place to go but our own pockets to find money for increases. Many of our owners have not been able to get the pay increases or bonuses this year. Some have lost their jobs.”

But the union countered that the city’s real estate industry had come through the recession relatively strongly, with rents projected to rise over the next several years. Their members also have to contend with the rising cost of living and cannot be expected to accept a deal that amounts to no real raise or perhaps a cut, union officials said.