Top executives of a bankrupt coal producer and the nation's biggest miners' union are trading public jabs over bargaining meant to stave off a strike against a company given a court's go-ahead to slash health care and pension benefits to thousands of workers and retirees, the Associated Press reported yesterday. The public feuding resurfaced on Wednesday, when the United Mine Workers of America accused Patriot Coal Corp. of walking out of negotiations meant to mitigate the bankruptcy judge's May 29 decision allowing Patriot to impose wage and benefit cuts by abandoning its collective-bargaining agreements. Patriot's chief executive Ben Hatfield fired back hours later, denying the company broke off talks it noted it was under no legal obligation to continue. Hatfield said the company had simply recessed to mull financial implications of the union's demands that Patriot roll back most of the cost relief the bankruptcy judge approved.