After an all-night bargaining session with the Metropolitan Transportation Authority(MTA), officials with the Transit Workers Union announced Friday morning that they would not accept the MTA's contract proposal, and would start a series of strikes to put pressure on the city.

Roger Toussiant, president of Transit Workers Union (TWU), said in a statement after the contract negotiation broke off that job action would begin Friday with the privately-owned Jamaica and Tri-Borough bus lines, before spreading to city buses and subways.

A city-wide strike would begin Monday at midnight if no contract agreement was reached before then.

"The contract they offered would leave the next generation of transit workers behind, and we will not accept that," Toussaint said Friday morning. "We have voted to begin a series of strikes that will start with private bus lines and then spread to MTA properties."

Sources say the MTA is offering a 9-percent raise over three years, but the union is seeking more.

There is no word on whether more negotiations have been scheduled at this time.

Nevertheless, New York City transit workers remain on the job this morning, providing at least temporary relief to the city's 7 million commuters. In addition, schools and businesses that had planned to open later if a strike was called are all opening on time.

If the job action proceeds as planned, it will be the city's first transit strike since 1980. City officials say a full-fledged transit strike would debilitate the city and cost billions of dollars.

Negotiators for the two sides had been facing a midnight strike deadline, but ended up working through the night once the deadline passed without an agreement. The MTA delivered the night's final offer at 4:30 a.m., after which TWU officials moved to their headquarters to consider the deal. Toussiant rejected the offer ata press conference shortly after 7 a.m.

The overnight bargaining session appeared to be tense. A littlemore than an hour before the midnight deadline, Toussaint appearedat a press conference where he criticized the MTA for failing to put forth what he felt was an acceptable offer. He was joined by several of the city's top union leaders, including the police union's Pat Lynch, and the teachers union's Randi Weingarten.

Half an hour later, MTA Chief Negotiator Gary Dellaverson took a break from the negotiations to defend the MTA's position, telling reporters that the MTA was doing all it could to hammer out a deal with the union.

Union sources said earlier this week they are willing to make some concessions, including a willingness to accept lower increases if the MTA agrees to scale back disciplinary actions.

According to the city comptroller's office, New York city would lose 1.6 billion dollars in the first week of a transit strike, with the hardest economic blow coming on the first weekday.

The price tag would also include employers who would move workers to smaller satellite offices and a possible drop in productivity if employees leave early to get a ride home.

If the buses and trains are not running over the weekend, it would cost the city about 200 million dollars, since there are fewer businesses open then.

After that, the cost of a strike would settle at about 250 million dollars per weekday as people figure out ways to get around.