Anoka-Hennepin teachers, frustrated about a lack of progress in contract talks with the state's largest school district, will now do only what work can be completed during the school day and is required by their contract.

That means the district's nearly 3,000 teachers will stop doing work after hours, including grading papers they haven't graded during the day, checking e-mails, tweaking lesson plans and voluntarily attending after-school events. It's called a "work-to-rule" action.

The local teachers union, Anoka Hennepin Education Minnesota, and district officials had their 13th negotiating session on Wednesday. It was also the first that included an outside mediator as the two sides try to reach a new two-year contract through 2014-15.

Across the state, 157 of the 334 districts tracked by Education Minnesota have reached contract agreements with their teachers.

Teachers are faring better in this contract cycle than in the prior one. The average salary increase has been 1.7 percent in the first contract year and 2 percent in the second, not including increases for experience and additional training. The average pay increase for the 2011-13 cycle was 1 percent in each of the two years, according to Education Minnesota.

In the Anoka-Hennepin district, local union President Julie Blaha said work-to-rule "really shines a light on what teachers do during the day. It really highlights how much our teachers are doing above and beyond for our students. We are asking the district to support that with a fair settlement."

Said district spokeswoman Mary Olson: "We continue to negotiate in good faith to reach an agreement."

Anoka-Hennepin teachers have proposed a 2.5 percent raise in each year of the contract and no change to benefits.

According to the union, the district's last offer, in December, was for a raise of 1 to 1.25 percent in the first year, depending on experience, and of 1 to 1.55 percent in the second year, and for teachers to pay more of future increases in health care costs.

District officials would not discuss specific offers.

"Over the last four years, we've made some significant sacrifices. About 60 percent of our teachers haven't had a raise in four years. Their salaries have been frozen," Blaha said.

"We have all been making sacrifices in tough times. As we start to turn a corner, it's time for our compensation to get back on track, too."

Currently, teachers' salaries in the district start at $37,000 and top out at $80,000 for those with more than 20 years of experience and advanced degrees.

Talks began late last May for the contract running from July 1, 2013, to June 30, 2015. The current pact remains in effect until a new one is reached.

In the last round of negotiations, the union and district settled in September 2011; the last work-to-rule action by Anoka-Hennepin teachers was in 2009.

Education Minnesota President Denise Specht said work-to-rule is "not a tactic that's used often. When locals decide to go down that road it means things are very serious. They don't take a decision like that lightly."

Talks elsewhere

Four of the state's five largest districts — Anoka-Hennepin, St. Paul, Minneapolis and Osseo — remain in negotiations with their teachers' unions. The Minneapolis district is in mediation with the Minneapolis Teachers Federation, and the two sides are scheduled to meet Thursday.

"We are making good progress," Teachers Federation President Lynn Nordgren said. "It's been a positive experience. The mediator has been very good about helping us narrow down the number of items."

"We want to make sure it's good for kids and fair for teachers," she said.

Minneapolis teaching salaries start at $38,000 and top out at $85,000 for those with advanced degrees and experience.

Class sizes, staffing and early education are at the center of negotiations between St. Paul schools and the teachers' union in that city.