The company is weighing its options as it waits on an incentive package from the state of Oklahoma. But even if Gerdau decides to stay, it says it will need to shut down the plant for 24 months to make upgrades for meeting environmental regulations.

The layoffs will take effect no earlier than Oct. 16, Gerdau says.

Robert Bullard, vice president and general manager of the Sand Springs mill, confirmed the layoffs in a statement Tuesday.

The 60-day notices are required by federal law.

Gerdau announced in June that it would shut down the mill. It then decided to listen to offers from the state that might keep the plant economically viable.