UFC, Fighter Spar Over Union Activity

Professional mixed martial arts fighter Leslie Smith is looking to unionize her fellow UFC fighters. But the effort might have knocked out her career with the largest MMA organization in the world, she alleges.

Smith says in an NLRB charge filed May 2 that the organization unexpectedly decided not to renew her contract, and she alleges the move was retaliation for union activity she began in February.

The UFC declined to comment.

The case also presents the National Labor Relations Board with the question of whether UFC fighters are accurately classified under labor law as independent contractors or should be ...