The NBA has filed a federal lawsuit against the league's players union, hoping to establish the legality of the lockout imposed a month ago, and to protect against a possible lawsuit.
League officials also announced they were filing an unfair labour practice charge against the National Basketball Players Association, claiming the union has not bargained in good faith.
The moves come the day after talks that produced no movement, and just over a month after the previous collective bargaining agreement between club owners and players expired, sparking the second shutdown in NBA history.