Consolidated Edison and a union representing nearly 9,000 of the utility's workers reached a tentative agreement Wednesday after "extremely contentious" contract talks, a spokesman for the union said.

Negotiations for the four-year contract had begun Tuesday in Manhattan but continued well after an 11:59 p.m. deadline the union had set for a possible walkout. But both sides agreed to "stop the clock" minutes before the deadline and negotiated through the early morning hours Wednesday to reach the tentative deal.

Joe Flaherty, a spokesman for the Utility Workers Union of America Local 1-2, said that the two sides negotiated a range of issues, including wages, safety and health care.

One of the major sticking points for the union - Con Edison's proposal to switch from traditional pensions to a 401(K)-style plan for new employees - was tabled by the utility "at the 11th hour," Flaherty said.

"I think they fully understood that this union and its members would not stand for a change in their long traditional pension," Flaherty said. The union represents about two-thirds of Con Edison's 14,000 employees.

The tentative deal also states that workers will get a wage increase. However, they will have to pay more out of pocket for health care.

Con Edison spokesman Michael Clendenin did not immediately respond to a request for comment early Wednesday.

Negotiations resumed Tuesday morning in Manhattan after they were suspended over the weekend when Gov. David Paterson intervened and suggested both sides take a cooling-off period.

The union had threatened to walk off the job early Sunday if an agreement wasn't reached but Paterson, expressing concern about the potential impact a strike would have on customers during hot weather, stepped in late Saturday.

Most of the union's workers maintain the utility's gas, electric and steam delivery systems for some three million customers in most of New York City and Westchester County.

The two sides didn't agree on what effect a strike could have had, with Flaherty arguing that a walkout would be "catastrophic," particularly for elderly and disabled customers. Con Edison, however, had insisted it could keep the power system running smoothly during a strike.

The utility had repeatedly pointed out that about half of its managers rose through its ranks and would respond to any emergencies if workers struck. However, non-emergency repairs and meter readings could be delayed, the utility had said.

In 1983, a strike by the union lasted more than two months. During that strike, a 20-block area including the garment district went dark for days after a water main break started an electrical fire in a substation. The blackout forced hundreds of offices and stores to close.

Gimbels and Macy's department stores used emergency generators.

Crews of Con Ed supervisors worked to splice power lines to other substations and bypass the destroyed transformers. Con Edison officials at the time said the strike had no effect on the company's response to the outage.

Con Ed workers will now have to vote on whether or not they will ratify the new contract. No date has been set for when the vote will take place.