BALTIMORE -- Jno. McCall Coal Co., one of the nation's largest coal exporters and a major customer at the port of Baltimore, is in bankruptcy proceedings and is considering going out of business.

The company filed Friday for protection from creditors in bankruptcy court after several creditors requested involuntary liquidation of the company's assets.

Although mainly known as a coal exporter, McCall has suffered losses related to several mines it owns and operates.

M. Philip Lehr, McCall's president and chief executive officer, declined to provide specific figures, but said the mining operations lost millions of dollars. Lehr, a former vice president of marketing, was appointed president in May.

A decision by Signet Banking Corp. of Richmond to revoke a $10 million line of credit earlier this year also severely damaged the profitable coal brokerage end of McCall's business, according to Barry Rosen, an attorney for Shell Oil Co., one of the creditors that sought liquidation of the company.

"Clearly, we have been struggling ... The board of directors made management changes in mid-May in the hopes of turning the company around, but the efforts may have been too late," he said.

In its filing in federal court in Baltimore, the company reported assets of $39.8 million and liabilities of $29.5 million with secured debts of about $3 million.