AK Steel Corp. , Middletown, Ohio, will voluntarily contribute $50...

AK Steel Corp., Middletown, Ohio, will voluntarily contribute $50 million to its defined benefit pension plan, according to a news release. The cash contribution follows an $84 million contribution made in May and a $150 million contribution made at the beginning of the year. AK Steel's pension plan, with $2.5 billion in assets, was underfunded by about $1.2 billion as of Dec. 31, according to the company's annual report.