Steve Mills has left his role as New York Knicks president, admitting he was frustrated by failing to find the formula to deliver success.

The announcement of his exit from the post came from the Knicks on Tuesday, with general manager Scott Perry appointed to oversee basketball operations on an interim basis.

Having ended a 10-year stint with the franchise in 2009, Mills re-joined the Knicks in September 2013 as general manager before taking on the role of president four years later.

However, the Knicks have been unable to make the NBA playoffs since. They sat 13th in the Eastern Conference this season with a 15-36 record at the time of his departure.

A statement from the Knicks said: "The New York Knicks today announce that Steve Mills will be leaving his position as president of the New York Knicks, effective immediately.

"The organisation will undertake an immediate search for a new team president. In the interim, Knicks general manager Scott Perry will oversee the Knicks basketball operations."

Mills thanked owner James Dolan for giving him the opportunity in the first place.

He said: "I will always be grateful to Jim for giving me the chance to represent this franchise and I'm disappointed we were unable to achieve success for New York."

The Knicks are owned by the Dolan-led Madison Square Garden Company (MSG), the organisation behind the eponymous midtown New York arena.

The NBA outfit and NHL team the New York Rangers, who like the Knicks play home matches at the famous venue, are poised to soon become part of a sporting division that breaks off MSG's entertainment business.

Mills previously held senior roles with MSG and looks set to return to a role within its new sporting set-up.

The Knicks' statement added: "It is anticipated that Steve Mills will be nominated to the board of the standalone sports company, following the completion of the proposed spin-off [of] the entertainment business, pending all necessary approvals, including by the MSG board."

Dolan, executive chairman and CEO of MSG, said: "Steve and I have come to the decision that it would be best for him to leave his role as president of the New York Knicks.

"We thank Steve for his many years of service to our organisation and look forward to continuing our relationship with him as part of our board."