AK Steel shares fell 3.6 percent to $11.10 in trading on Tuesday amid news of the company's lockout of nearly 2,700 hourly union workers after their contract expired without a new agreement. The company will use temporary workers to continue filling orders, according to a company spokesman.AK Steel Holding Corp. and it's union workers disagreed over the company's demand for a reduced work force, freezing of pensions and an increase in employee's health care contributions. Union members had recently voted to allow union leaders to authorize a strike if negotiations failed. Brain Daley, president of Armco Employees Independent Federation said the union had offered to continue working under the terms of the existing contract, but the company refused. Both sides have agreed to continue negotiating, but no talks are currently scheduled. "We have been trying to do everything we can to get a contract," Daley said. AK Steel produces flat-rolled carbon, stainless and electrical steels, along with tubular steel products, for customers in the automotive, appliance, construction and manufacturing markets.