Tony Rea has resigned as director of sport at Harlequins RL to pursue a career in coaching within the game.
Rea has been an integral part of the Broncos and Quins years
The move ends his 13-year association with the club after joining the then London Broncos as a player in 1994.
Rea became chief executive officer in 1996 and coach from 2000 after spells as caretaker coach before joining the board of directors in 2006.
The Australian, 41, said: "I've missed coaching at the highest level, and will pursue opportunities to do so."
Rea led the Broncos, who linked-up with Harlequins rugby union club in 2006, to the Super League play-offs in 2003 and 2005.
He continued: "I wish to thank the club for the many things that it has given me. My experiences here have developed and broadened me.
"To everybody involved now and in the future, I just ask that you continue to look after the place in the same way."
Harlequins RL director David Hughes added: "We respect Tony's decision to further his career in coaching, which I know is in his heart.
"I've known Tony as a player since the start of Super League in 1996. Thereafter, he filled the role of chief executive officer and first team coach as a complete professional.
"With the nature of the former London Broncos club and now Harlequins RL, Tony has had to do many tasks beyond the call of duty.
"And on behalf of our club we wish Tony good fortune in seeking this new career."
Ian Lenagan, Harlequins RL chairman, said: "We are desperately sorry to see Tony go but cannot stand in his way after all that he has given over the years to Broncos and Harlequins.
"Tony's skills in game analysis, tactics, player identification and motivation are of the highest order and some club soon, whether in Australia or in the UK, will gain a superb coach."
It is expected that Rea will stay with the club over the next few months to help the transition and wait for the right opportunity in coaching.