PITTSBURGH—Duquesne University in Pittsburgh is appealing a National Labor Relations Board order that a vote to unionize by the school's part-time faculty should begin Friday.

The university is appealing the NLRB's rejection of the private, Catholic school's claim that it should be given a religious exemption and be allowed to withdraw from a previous agreement with the United Steelworkers union to allow the election.

The union announced last month that the school agreed to let adjunct faculty at the university's McAnulty College and Graduate School of Liberal Arts vote for two weeks beginning June 22. The votes were to be submitted by mail and counted on July 9.

The union contends most of Duquesne's roughly 130 part-time faculty members want to form a bargaining unit.