Last week, officials from the school district and the teachers union stood together to praise a long-awaited teacher contract that both sides described as "historic" and "groundbreaking."

Superintendent Arlene Ackerman even said that the new, three-year deal - which includes a 3 percent raise in the fall, and another in 2012 - would put Philadelphia on the map because of new provisions that include the possibility of bonuses and changes to teacher assignments in some schools.

But a group of district teachers and a coalition of education groups staged demonstrations outside district headquarters yesterday to say that the contract was anything but perfect.

About a dozen teachers protested a proposal in the contract that gives the district the flexibility to implement reforms under the district's proposed Renaissance schools initiative - one of the key components of Ackerman's reform plan. It would convert low-performing schools into charters or turn them over to outside managers.

Michael Roth, a teacher at Edison High, said at the protest that Renaissance is "a terrible idea." In Chicago, where Renaissance schools have been tried, he said, "the research proves that students are at a par or worse than other public schools."

The teachers said that they don't like the idea that the Renaissance model would allow administrators to require teachers to work longer school days, two Saturdays a month and 22 days in July.

"We have families," Roth said.

They expressed concern that the Renaissance schools, the first of which was to be announced at today's School Reform Commission meeting, will drive veteran teachers out of the district and into suburban schools.

All Renaissance schools will be shut down but up to 50 percent of the faculty may be rehired when the schools are reopened under new management.

District spokeswoman Evelyn Sample-Oates said that the protesting teachers may not understand the model.

The initiative would in fact provide teachers and their students a "fresh start," she said.

"We're going to make sure they have a job," she said of affected teachers. "But you've got to try something drastic. These schools have been failing for some time."

All the protesters said that they voted against the new teacher contract, which the PFT rank and file approved by a vote of 1,831 to 885 last Thursday.

Ken Flaxman, a teacher at Hartranft school, said that if the school became a Renaissance school, the new schedule would interfere with his family life.

"I love teaching," Flaxman said, "but I coach my kids' soccer and basketball games. To be forced to [teach] two Saturdays a month . . . . "

Olney High West teacher Lauren Vargas said that the principal at her school is a graduate of Olney, and thus understands the school's culture and climate.

Vargas said she fears that the Renaissance schools will damage progress already made.

"This will disrupt the culture and any sense of achievement that is already taking place," Vargas said.

At a separate protest a few feet away, Lauren Jacobs, with the Cross City Campaign for School Reform, a coalition of education groups that lobbied during negotiations, said that more work needed to be done.

"While we're pleased with the new level of collaboration in the contract, we also see a huge missed opportunity of strengthening incentives to get and keep teachers in struggling schools," she said.

Bartram High history teacher Hye-Won Gehring, of the Teacher Action Group, said that she's hopeful that the contract will "bring about more professionalism to our field."

"However," she added, "the real work lies ahead. As always with promises, initiatives and new programs instituted by the district, the devil is in the details."