Patriot Coal Corp., the bankrupt mining company, said sharp declines in demand for coal could cause it to default on loans this year if it can’t change its current loan agreement, Bloomberg News reported yesterday. Over the past year, falling prices for metallurgical coal have cut into the company’s earnings forecasts, Patriot said in court papers filed on July 30. The St. Louis-based company filed for bankruptcy in July 2012, citing a drop in demand and $1.6 billion in lifetime health care obligations for its retirees. Patriot is seeking court approval of a proposed amendment to a $375 million loan, which lenders have already consented to. Under the previous loan agreement, Patriot was required to have a minimum of consolidated earnings of $205 million by Dec. 31. The proposed amendment would drop the threshold to $101.3 million.