A federal appeals court has temporarily blocked a major deregulation decision of the Interstate Commerce Commission by halting the merger of the nation's second-largest railroad and largest barge company.

The 6th U.S. Circuit Court of Appeals in Cinncinati yesterday granted a stay postponing the acquisition by CSX Corp., the Richmond-based railroad holding company, of American Commercial Barge Lines Co.

The ICC had approved the merger last July and scheduled it to go into effect Sunday.

The court said the merger raised the possibility of "serious and far-ranging consequences" and ordered it held up at least until after a court hearing Wednesday.

The court will decide then whether to allow the acquisition or to postpone it further while the full court reviews the case.

Barge operators, coal carriers, electric utility companies and others have challenged the ICC's decision to approve the merger, arguing that it will reduce competition in transportation of coal for export and raise coal prices.

The National Coal Association yesterday praised the court's action and said that, "If the ICC is allowed to prevail, the coal industry will be adversely affected and consumers eventually will pay higher prices for electricity."

CSX has argued that its purchase will lower coal prices by creating a more efficient transport system.

CSX is "very optimistic" that the ICC's decision will prevail in court, said corporate spokesman Edwin Edel. "We believe the commission conducted a very thorough review over a six-month period. . . . We believe our position will be upheld."