Tony George has left the board of Hulman & Company with immediate effect, citing a potential conflict of interest between his remaining on the board of the owners of the IZOD IndyCar Series and his involvement with a takeover bid by a group of team owners.

The announcement was made on Friday afternoon, and was the first official confirmation that George was indeed fronting a buy-out bid for IndyCar by a number of team owners.

However, in making the announcement, Hulman & Company president and CEO Jeff Belskus insisted that the series was not for sale and that the owners were not considering any offer that had been submitted to it for a buy-out by any party.

"Tony George has made the difficult decision to resign from the board because of his involvement with a group that has recently expressed an interest in purchasing the Hulman & Company-owned IndyCar organization," said Belskus.

"While the business is not for sale and no offers to sell it have been considered or are being considered, we applaud Tony's efforts to resolve the appearance of a conflict and appreciate the gravity of this decision," he added.

George was previously president of the Indianapolis Motor Speedway from 1990-2004 which is also owned by Hulman & Company. He set up the Indy Racing League which split away from CART as the sanctioning body of open wheel racing in the US leading to a decade-long schism in the sport until reunification in 2008. George also set up and ran Vision Racing, and is now co-owner of Ed Carpenter Racing with his stepson, owner-driver Ed Carpenter.

"Tony has been involved with our businesses for many years and has contributed significantly through his leadership role with IMS and IndyCar and as a member of this board," said Belskus, who added that George's place on the Hulman & Company board woud not be filled. "We wish Tony much success in the future."

In response, George said in a statement: "I realize that my recent efforts to explore the possibility of acquiring IndyCar represent the appearance of a conflict, and it is in everyone's best interest that I resign from the Hulman & Company board.

"It goes without saying that I want to do what is best for this organisation," he added.

The latest round of takeover rumours surfaced in the Sports Business Journal at the beginning of October, with the newspaper's sources stating that the board of Hulman & Company had received a definite takeover offer from an investment group said to include Chip Ganassi, Roger Penske, Michael Andretti and Kevin Kalkhoven (co-owner of KV Racing Technology), and fronted by George.

The reports suggested that the offer from the group would result in the group taking over the running of the loss-making series and assuming any outstanding debts, while Hulman & Company would retain its majority stake and management of the IMS venue.

Motorsports marketer Zak Brown was also said to be involved in the group and being lined up as a potential CEO to replace Randy Bernard. Another potential candidate for the post was Andretti Autosport's executive vice president and chief operating officer John Lopes or Daytona International Speedway's president Joie Chitwood III, a former chief operating officer at IMS for seven years when George was the CEO there.

Initial opinion was undecided as to whether George's resignation from the board of Hulman & Company made a successful takeover by the car owners more or less likely in the coming months.

Quitting the board means that George is now free to take a more proactive and aggressive line in his bid to acquire ownership, but his resignation might also indicate that the bid is not finding favour among the other Hulman-George family members on the board.

George was forced out of his position as IMS CEO in 2009 by a board vote, and also resigned as the series CEO in the wake of the reunification at the same time. He's rumoured to have already tried one unsuccessful buy-out move for the series already in 2010.