A union lawyer negotiating with Walter Energy Inc. said that miners would rather gamble jobs at the bankrupt coal producer than make additional concessions, a stance the judge called “a game of chicken,” Bloomberg News reported yesterday. Walter Energy filed for bankruptcy in July and is set to put its assets up for auction Jan. 5. As an opening bid, lenders have offered to exchange $1.25 billion in debt and pay $5.4 million in cash. That agreement hinges on a consensual resolution with unions or court approval to reject collective-bargaining agreements. The union’s lawyer told Bankruptcy Judge Tamara O. Mitchell yesterday that issues involving worker safety were too important to bargain away. Judge Mitchell cautioned that under such a strategy, the union “stands to lose everything.” If the union wins, “the buyer walks because there’s no sale and then all the employees are out of a job, the mines close down” and there won’t be benefits for anyone, Judge Mitchell said. Sharon Levine, the attorney for the United Mine Workers of America, said that the union’s stance is “not a threat.”