Tony George has resigned from his position as head of the Indianapolis Motor Speedway and the IndyCar Series following a meeting of the board of directors of the Hulman-George company that owns the legendary racetrack and the championship.
His role as president and CEO of Hulman & George Company will be taken by W Curtis Brighton, currently the group's executive vice president and chief legal counsel, while executive vice president and chief financial officer Jeffrey G Belskus will become president and CEO of the Indianapolis Motor Speedway Corporation.
George will remain on the board of directors, and will continue to run his Vision Racing team in the IndyCar Series.
Earlier this month Indianapolis released a statement refuting American media reports that George had been ousted, but acknowledging that he had been asked to devise a plan for the management of the family companies "that would allow him to focus on the business which requires the greatest attention".
Chairman of the board Mari Hulman George said the Indy Racing League founder had ultimately decided to stand down from his position instead.
"Our board had asked Tony to structure our executive staff to create efficiencies in our business structure and to concentrate his leadership efforts in the Indy Racing League," she said.
"He has decided that with the recent unification of open-wheel racing and the experienced management team IMS has cultivated over the years, now would be the time for him to concentrate on his team ownership of Vision Racing with his family and other personal business interests he and his family share.
"Tony will remain on the Board of Directors of all of our companies, and he will continue to work with the entire board to advance the interests of all of companies."
Hulman George is confident that Brighton and Belskus will be able to take the companies forward.
"Jeff and Curt have both been with the company for many years in positions of top leadership," she said. "Tony, as well as the entire Board of Directors, has the utmost confidence in their capabilities.
"Both of these men have years of experience and leadership within our companies. In addition, each of our companies has effective presidential leadership, and that will remain in place."
After reports that George's position was in doubt first broke, the IndyCar team owners issued a statement expressing their full support for him, amid speculation that changes to the board could jeopardise the championship and suggestions that George's family were unhappy with the amount of money he had spent on the series.
But Hulman George insisted that the Indianapolis management remained committed to the IndyCar Series.
"These changes underscore our family's commitment going forward to all of our companies, especially our commitment to the growth of the Indy Racing League and the sport of open-wheel racing," she said.
"We believe the Hulman-George family's long stewardship of the Indianapolis Motor Speedway, beginning in 1945, and our significant investment in the Speedway and in the IRL demonstrates that we have full confidence in all of our companies and that we intend to grow them in the future."
George took over the leadership of the Indianapolis companies in 1990. He controversially founded the breakaway Indy Racing League in 1996, but was later instrumental in the 2008 reunification with the rival Champ Car World Series.
Establishing and sustaining the IndyCar Series required substantial and prolonged investment by the Hulman George companies, which also provided significant financial assistance to smoothe the merger last season.
During George's leadership Indianapolis also added a NASCAR event to its schedule for the first time, and brought Formula 1 back to America on an infield road course, which is now used for MotoGP after the track failed to agree a new F1 deal with Bernie Ecclestone.
Hulman George paid tribute to George's achievements over the past 18 years.
"Our family and the entire racing community are grateful to Tony for the leadership and direction he has provided since 1990," she said.
"We are pleased that he will continue to be an important part of the Indy Racing League as a team owner and as a member of our Board of Directors, and we wish him every success."
His successors Belskus and Brighton have been with the IMS companies since 1987 and 1994 respectively and have long held executive positions.
George's Vision Racing operation, which is now set to become his primary focus, was founded in early 2005 but has yet to win a race. It recently scaled back to a single car for Ed Carpenter due to a lack of funding, with Carpenter's former team-mate Ryan Hunter-Reay moving to AJ Foyt's team.