ATP executive chairman and president Brad Drewett will step down from his position after being diagnosed with Motor Neurone Disease, it has been announced.

The Australian took on his current role in January 2012, having previously been a member of the ATP Player Council and ATP Player Board, as well as CEO of the international region and tournament director of the ATP World Tour Finals.

Drewett, 54, will continue the job on an 'interim basis' until the ATP board of directors appoint his successor.

"It has been a privilege to serve as executive chairman and president of the ATP, an organisation that I've been a part of for more than 35 years since I became a professional tennis player," said Drewett.

"I hold the ATP very close to my heart, and it's with sadness that I make the decision to enter this transition period due to my ill-health."

Drewett has been part of the ATP as a player and executive since 1977.