NEW YORK — Steel Dynamics Inc.’s fourth-quarter net income more than doubled to nearly $60.6 million from $30.2 million a year earlier, primarily due to a strong performance by its metals recycling division and improved demand for steel sheet from automotive and manufacturing.

But sales by the Fort Wayne, Ind.-based steel producer and metal recycler fell 8.3 percent to $1.71 billion from $1.86 billion as a result of weak long products shipments and lower overall steel metal spreads, the company said.

Improvements in sheet steel volumes balanced out the overall decrease in sales, chief executive officer Mark Millett said in a statement. "The fourth quarter was challenging on a number of fronts, but the team did a great job. Automotive and manufacturing provided improved sheet demand, while nonresidential construction remained weak."

Millett said the company was optimistic for 2013 due to improvements in the residential and nonresidential construction markets. "Recent housing starts data suggests potential improvements in residential construction, and there are areas across the U.S. indicating signs of strengthening in the nonresidential construction sector, although levels remain historically low," he said.

The company posted full-year net income of $163.6 million, down 41.2 percent from $278.1 million in 2011 on net sales that fell 8.8 percent to $7.29 billion from almost $8 billion.