MIAMI -- In an apparent 12th-hour maneuver to trim the budget for Miami-Dade County Public Schools, Superintendent Rudy Crew on Thursday stripped millions of dollars in raises from about 33,000 teachers and staff that had recently been negotiated.

United Teachers of Dade President Karen Aronowitz said Crew sent her a letter stating he was cutting off raises for all school district employees and that union contracts would be renegotiated. Aronowitz said the letter was sent after business hours Thursday.

The raises were supposed to take effect July 1.

"We're very upset," Aronowitz said. "When people negotiate, they come to the table and they come to an agreement. We are returning to a table where the agreement has already been done."

The action effectively freezes the salaries of those employees who were expecting to receive raises, but it saves the school district more than $40 million of the $284 million needed to trim the budget for the upcoming school year. It also breaks the union contract negotiated upon and agreed to earlier this year.

"We might call it theft because we have contractually-agreed salaries for 2008-09, and yet we're called back and told that we're going to stay at the 2007-08 levels," Aronowitz said.

Earlier this month, Crew said he would not take a pay cut to help balance the budget. He wasn't in his office for comment Friday.

"We will be going forward (in negotiations)," Aronowitz said. "We will continue to meet with the district, but this is legal trickery and it is a violation of our contract."