Mixed martial arts star Conor McGregor is in plea negotiations to resolve charges stemming from a backstage melee at a New York arena.

The 29-year-old Irish fighter and co-defendant Cian Cowley remained free on bail after a brief court appearance on Thursday. They are due back in court on July 26.

A prosecutor said plea negotiations are continuing.

Outside the court in Brooklyn, McGregor said he regrets getting in trouble and hopes to have the court case resolved soon.

Video footage showed McGregor hurling a trolley at a bus full of fighters after a press conference for UFC 223 at Barclays Centre in Brooklyn in April.

Fighters Michael Chiesa and Ray Borg were injured by shattered glass and unable to compete.