The Australian Turf Club has paid tribute to the career and achievements of outgoing Racing NSW Chairman John Messara following his decision to retire at the end of the year.

Messara announced on Monday he would step down in December having achieved what he set out to do in his five years at the helm of racing in the state.

ATC Chairman Laurie Macri said Messara had been involved in some of the biggest and most important changes to Sydney racing since the Sydney Turf Club and Australian Jockey Club merged to form one entity.

"We are very grateful for the strong partnership we have continued to build with Racing NSW since the merger in February 2011," Macri said.

"I particularly commend John's role in working with the ATC to secure the deal with SKY Racing to showcase Sydney racing to the world.

"I am grateful for what I have learned from John's talents as a leader, as are I am sure countless others in the racing industry for whom John has been a wonderful mentor.

ATC chief executive Officer Darren Pearce said greater integrity and animal welfare improvements, increased funding for prize money and infrastructure, and development of The Championships were some of the major highlights during Messara's tenure.

"The ATC honours the career of John Messara and thanks him for his outstanding service and leadership," Pearce said.