The St. Paul School District and the union representing its teachers have agreed to set aside an entire week to try to negotiate a new two-year contract and, in turn, avert a strike.

In talks Friday lacking major breakthroughs, the two sides moved to expand next week's mediation calendar from one day, Wednesday, to a weeklong effort, district spokeswoman Toya Stewart Downey said.

The decision came in a session held two days after members of the St. Paul Federation of Teachers voted to authorize a strike against the district beginning as early as Feb. 13.

Friday's session ran from 9:30 a.m. to about 5 p.m., without participation from school board members or Superintendent Joe Gothard.

Board Chairwoman Zuki Ellis did, however, provide a letter to negotiators Friday stating: "We believe that there is a way forward, and that we all can negotiate our differences and continue to work hard for all of our kids."

In an update to teachers, the union's bargaining team said it, too, was committed to settling the contract and avoiding a strike. But it expressed disappointment over a lack of progress in Friday's talks, and frustration over what it described as the district's unwillingness to tap reserve funds to help pay for a new deal.

There are major differences to resolve.

This year, the district took a new approach to bargaining by stating upfront that it would limit contracts to 1 percent of current salary costs, or about $2.1 million in new spending for teachers. The district has estimated the total cost of the union's proposals at $159 million.

Typically, salary provisions are key to a labor deal, and St. Paul's contracts have been generous. The average salary for a St. Paul teacher is about $76,000, tops in the state.

The union has proposed 2.5 percent pay increases in each year of the contract. The district is offering 1 percent increases, and has stated that the cost of any other union proposals would have to come out of the money earmarked for the 1 percent raises.

Both sides generally support efforts to lower class sizes, increase support staff members and test new approaches to discipline referred to as "restorative practices." The challenge will be in identifying what is affordable in a time of chronic budget shortfalls.

The union proposes replacing class size ranges with hard caps that are at the low end of the ranges. The district has offered to keep the current ranges intact for schools at 95 percent capacity, but wants the flexibility to grow enrollment in the remaining buildings.

The union said the district's proposal would increase class sizes at 29 elementary schools. The district said the caps sought by the union would cost $91 million in new teachers alone.

Two years ago, the union and the district agreed to have schools pilot new approaches to discipline emphasizing relationship-building over punishment. Programs now are in place at nine schools, with an agreement to add three in 2018-19. The union proposes to add two pilot schools per year beginning in 2019-20.

In 2014 and 2016, the union persuaded the district to add new support staff members and teachers of English language learners.

Now, it wants every school to have a nurse and librarian, plus social workers and counselors in numbers determined by staff-to-student ratios. The district opposes the use of ratios, saying greater flexibility is needed to run schools based on the needs of the students they have.

Talks are scheduled to resume at noon Monday.

Anthony Lonetree • 612-673-4109