Experienced administrator Ian Mackay has resigned his role as chief executive of The Championships, the two-day centrepiece of the Sydney autumn racing carnival held for the first time this year.

Mackay will step down next month to take over at the helm of the Canberra Southern Cross Club.

Racing NSW boss Peter V'landys said the governing body was disappointed to lose Mackay who was instrumental in enticing two international runners to Sydney for the autumn.

"The success of The Championships in 2014 was in a large part due to his knowledge, experience and commitment to the creation of the pinnacle event for NSW thoroughbred racing," V'landys said.

"Whilst we would have preferred Ian stay on as CEO of The Championships, we understand his reasons for seeking a new challenge and wish him every success."

Mackay held roles with Tabcorp and the Australian Turf Club before joining Racing NSW in November.

"I know I will miss the racing and wagering industry," he said.

"There are some shared experiences I will never forget and the inaugural running of The Championships including the recruitment of Hana's Goal from Japan and Gordon Lord Byron from Ireland rank high amongst those."