A group of New York Knicks fans have started a website to urge owner James Dolan to sell the NBA franchise.

Dolan has been in the spotlight this week after it was revealed that he emailed a frustrated fan to tell him to support rivals the Brooklyn Nets following criticism of the team, who currently hold an NBA-worst 10-42 record.

Brothers Jason and Jared Koeppel, with help from friends Greg Kohler and Dan Filowitz, have responded by launching a site which is hoping to raise enough money for a billboard to encourage a sale.

"This email that he had the nerve to send to one of his fans was the moment. We talked last night - the four of us - and just said, you know what, we've had enough and we've got to do something," Jason Koeppel told ESPN.

"We've been patient, and the cost of going to games has just skyrocketed to the point of being completely out of control, so we don't attend as many games anymore, but we definitely watch on TV, and it's just one terrible season after the other.

"We're sick of having Dolan around. We're sick of his meddling. He's an embarrassment. And it's embarrassing to us to read the email that he sent to a fan, so we just felt like it was time to embarrass him."

The group of friends were behind a similar campaign last year which resulted in the firing of New York Jets general manager John Idzik.