By Anthony Lonetree  anthony.lonetree@startribune.com

St. Paul Mayor Chris Coleman, citing school district gains in raising graduation rates, offered a nudge to district and St. Paul Federation of Teachers negotiators to reach agreement on a new teachers contract.

"I urge you to come together and find a solution so that we can continue the important work of educating the next generation and finally close the achievement gap," Coleman wrote in a letter Wednesday to Superintendent Valeria Silva and union President Mary Cathryn Ricker.

Union and district negotiators are scheduled to meet with a state mediator in a 12-hour session Thursday — four days before union members are set to vote on whether to give their leaders permission to call a strike.

Ricker, who has said that the strike-authorization vote could be called off if significant progress is made toward union goals, said of the mayor's input: "I really, really appreciate the community's interest in our work and their support for our focus toward a settlement."

Silva has stated she was willing to work nights and weekends to reach a deal. Her negotiating team is hopeful, too, that the district can avert a strike.

"To us, a strike is the worst possible outcome," said Matt Mohs, the district's chief academic officer. "There is no winner in a strike."

The district has maintained it cannot afford what the federation wants. On Tuesday, officials put the potential price tag of the union's contract proposals at $158.6 million.

To date, both sides have played down wages and benefits as a major sticking point. The current average St. Paul teacher salary is $68,436 — part of a wage-and-benefit package totaling about $92,000. The district has proposed salary and benefit increases totaling $16.6 million, or 6.6 percent over two years, compared with the union's proposal for $25.4 million in total wage and benefit increases, according to the district's latest projections.

The union, which called upon community members to help it craft its proposals, wants to reduce class sizes and increase support-staff members, including nurses, counselors, social workers and media specialists, and has taken issue with the district's projections of how many teachers and other employees would have to be hired under its proposals.

Gaining clarity on those estimates will go a "long way to understanding the room with which we can make progress on class size and staffing," Ricker said.

The largest ticket item, at $31.1 million, would be the move to reduce class sizes, a proposal that the district said would require hiring 347 new full-time teachers — at the $92,000 in wages and benefits now going to the district's average-paid teacher. Mohs acknowledged that some teachers who are new to the profession would start at a lower pay scale. But, he said, using that average figure is standard district budgeting practice.

Ricker said that the district's projections do not take into account the union's recent offer to give it flexibility on class-size limits. Nor does the district take into account the possibility of teachers who now are on special assignment being redeployed back into the classroom, she said. Still, Ricker said, she was optimistic about Thursday's mediation session.

Coleman, ready to help, said: "St. Paul has a long history of peaceful labor relations, and I hope that will continue."

Anthony Lonetree • 651-925-5036