Fort Wayne-based Steel Dynamics Inc. plans a $76 million expansion in Pittsboro, the company announced Thursday.

The company said its board of directors has approved the expansion, slated for completion in the second half of 2013, pending necessary permits. The company also expects “state and local government support,” according to the announcement.

Steel Dynamics employs 387 people in Pittsboro and plans to hire 50 more over the next two to three years because of the expansion, said Barry Schneider, vice president and general manager of the Pittsboro-based Engineered Products Division. Pittsboro is about 15 miles west of Indianapolis in Hendricks County

Steel Dynamics is the state's fourth-largest public company in annual revenue. The company had sales of about $8 billion in 2011.

About 6,500 people overall work for Steel Dynamics, including more than 3,000 in Indiana.

Steel Dynamics bought the Pittsboro mill in 2002 after it had been idled for more than a year following a bankruptcy. Qualitech Steel built the mill in 1996.

The Pittsboro mill produces “special-bar-quality,” or SBQ, steel bars. The mill’s capacity will increase 52 percent, from 625,000 tons a year to 950,000 tons a year, the company said. The expansion will also add to Steel Dynamics’ offerings of small-diameter bars, which are used in a variety of transportation, energy and automotive applications.

Steel Dynamics said the expansion would place Pittsboro among the largest SBQ producers in North America.

“Our customers have encouraged us to expand our product offerings as means of further establishing the Pittsboro facility as a ‘one-stop shop’ for all of their SBQ needs,” CEO Mark Millett said in a prepared statement.