Negotiators for the United Federation of Teachers and the Bloomberg administration worked late into the evening yesterday to hammer out a contract for the city’s 83,000 teachers that some officials said could be finalized as early as today.

The union and the city resumed formal negotiations last Monday for the first time since an impasse was declared in December 2004. The teachers have been working without a contract since May 2003. Both sides have agreed to use the recommendations of a state arbitration panel as the basis for a new contract, but they still can’t agree on the details.

The arbitrators have suggested an 11.4% total raise over three years for city teachers in exchange for several concessions and productivity increases, including lengthening the school day by 10 minutes, returning teachers to hallway and cafeteria patrol, and eliminating some seniority rights.

The union set an early October deadline for the mayor and has threatened that if a deal is not struck by that time, the city’s teachers could either go on strike or endorse Mayor Bloomberg’s Democratic challenger, Fernando Ferrer.

Under the state Taylor Law, public school teachers are forbidden from striking and can face fines and jail time. They would also lose two days’ pay for each day out of work.

The union asked the state’s Public Employment Relations Board to get involved in December. The three-person panel delivered its recommendations last month.

The panel’s suggested pay hike would boost teacher starting salaries to about $43,00 from roughly $39,000. The top teacher salary would go to about $90,000.

While Bloomberg aides had first said that they agreed with aspects of the report and disagreed with others, the mayor indicated last week that if a deal is not struck in a couple of weeks, both parties should agree to all of the arbitration panel’s recommendations.

If negotiators reached an agreement, the contract would still have to be ratified by a majority of the union’s executive board, delegate assembly, and full membership.

The contract is significant not only for the teachers whose compensation it governs, and for the mayor whose political fortunes it could affect, but also for education quality in the city’s schools, according to many observers. The union argues that higher pay attracts and retains better, more experienced teachers, while management says that some of the other provisions in the contract restrict principals from making decisions to manage schools.

The negotiators were meeting at the union’s headquarters at 52 Broadway.