After months of negotiation, New York state education officials and the state's teachers unions reached a deal on a new teacher evaluation system Thursday. 

The two sides worked through the night Wednesday in order to make the deal hours before a deadline set by Gov. Andrew Cuomo. If the two sides had not made an agreement, Cuomo said that he would have written his own evaluation system to put into the budget.

Under the new system, the rating will be based on two deciding factors: 40 percent of the decision will be based on standardized test scores by the state and districts, while 60 percent will be based on subjective means, including classroom observations and teachers presentations. Under the new system, teachers will also be able to appeal their ratings if they do not agree with them.

The deal, announced at a press conference in Albany Thursday afternoon, could save $700 million in federal funding for New York schools as a part of their participation in the Race to the Top program. It also settles a lawsuit filed by New York State United Teachers.

However, Mayor Michael Bloomberg still plans to go ahead with his plan to overhaul at least half of the teaching staffs at 33 of the city's schools. Bloomberg, who spoke at a press conference shortly after the Albany anouncement, said that it would take two years for the schools' worst performing teachers to get ratings that would get rid of them.

It would be unconscionable for us to sit around for two years and do nothing, the mayor said at a news conference at City Hall shortly after the governor's announcement. 

United Federation of Teachers President Michael Mulgrew, though, has said that the New York City-based teacher's union will take legal action if the mayor does not rethink his proposal.