Bally filed a lawsuit against Donald Trump.

The Chicago-based casino operator and the world’s leading producer of electronic game devices sued the real estate developer in U.S. District Court in Camden, N.J., in an attempt to stymie any hostile takeover bid. Bally Manufacturing directors also erected further takeover barriers by giving shareholders special stock purchase rights and by retaining Drexel Burnham Lambert to explore ways to restructure the company. The lawsuit, filed Friday, alleges that Trump violated federal securities and antitrust laws.