DES MOINES, Iowa (AP) -

Contract negotiations between Gov. Terry Branstad and the largest state workers union have moved to binding arbitration, with an award expected in early March.

Danny Homan, president of Iowa Council 61 of the American Federation of State, County and Municipal Employees, says Thursday that both sides have presented arguments to a neutral arbitrator. He says the two-year contract is expected March 7.

The union, which represents about 20,000 workers statewide, has clashed with Branstad over terms. Branstad has called for union members to start paying a portion of their health care costs, while the union is seeking to maintain current health benefits and 3 percent raises over the life of the contract.

Contracts have been settled through arbitration just twice since state workers started collective bargaining in 1977.