Bankruptcy Judge Shelley C. Chapman yesterday allowed LightSquared to move forward with its lawsuit against Dish Network Corp. and Chairman Charlie Ergen over his purchases of LightSquared debt before Dish bid for the wireless satellite company's assets, Dow Jones Daily Bankruptcy Review reported today. Judge Chapman denied a bid by Dish and Ergen to dismiss the suit, allowing LightSquared to go after Ergen on its charge that he bought the debt on behalf of Dish and not himself. Such purchases would have been illegal under LightSquared's credit agreement, which prohibited competitors from buying the debt.