The professional tennis tours and two other defendants jointly filed a motion in federal court in New York to dismiss the class-action antitrust lawsuit filed by the Professional Tennis Players' Association , a group co-founded by Novak Djokovic .
The PTPA sued the WTA women's tour, the ATP men's tour, the International Tennis Federation ITF and the International Tennis Integrity Agency ITIA, which oversees anti-doping and anti-corruption efforts in the sport, in March, calling them a "cartel."
The players are seeking a greater share of revenues and also raised various other complaints about how tennis is structured, including limits on prize money and a lack of competition from rival tours or tournaments.
The PTPA was founded by 24-time Grand Slam champion Djokovic and Vasek Pospisil with the aim of representing players who are independent contractors in a largely individual sport.
The group's executive director, Ahmad Nassar, repeatedly has said it is not a full-fledged union, does not have members and does not collect dues - all of which are pointed to in one of Tuesday's motions as reasons why the PTPA does not have standing as a plaintiff in the case. That motion came from all four defendants.