Derrick Walker has resigned as president of competition and operations for the Verizon IndyCar Series with effect from August 31, meaning that the 70-year-old motorsports veteran will leave his position at the end of the current season which concludes with the GoPro Grand Prix of Sonoma.

"I have appreciated the opportunity to work closely with the team owners, drivers and the team at IndyCar," said Walker. "After two and a half racing seasons, I believe the timing is right to move on to other opportunities."

Walker took up the post in May 2013 and during his tenure has overseen the addition of new aero kits bodywork technology to the cars and spearheaded additional investment in technology to help officials in race control during race weekends.

He's also seen the addition of the Grand Prix of Indianapolis and the forthcoming event at Boston to the championship season line-up, and his focus on continuous safety advancements has resulted in changes to the IndyCar underwing, making the cars more stable and strengthening sidepods, further protecting drivers.

"We have benefited from Derrick's extensive racing experience, his tireless effort and his passion for IndyCar, and he will be missed," said Mark Miles, CEO of IndyCart's parent company Hulman & Co., making the announcement on Thursday that Walker is to leave.

"We appreciate the thoughtful way Derrick has planned his transition and wish him well in his future endeavours," Miles continued, adding that a search for Walker's replacement was already under way.

Walker's strong background in team management in a variety of motorsports fields made him a popular appointment within the paddock. Born in Scotland, he started in the sport as a chief mechanic for the Brabham F1 team in 1970 before moving to Penske where he rose to become vice-president of racing, and during his time there the team won four series championships and four Indianapolis 500 titles.

Walker then took over the Porsche IndyCar team in 1988 and renamed it Walker Motorsports, enjoying success in the 1990s with Scott Goodyear, Robby Gordon, Paul Tracy and Gil de Ferran while also teaming up with Sarah Fisher in the Indy Racing League.

In 2004, Walker sold a share of the business which was soon rechristened Team Australia. The team signed up future IndyCar Series champion Will Power to race alongside Alex Tagliani while also moving into the Champ Car Atlantic Championship with drivers James Davison and Simon Pagenaud. Power provided Walker's first win as a team owner since 1999 when he won the inaugural Las Vegas GP in April 2007.

Throughout Walker's 19 years as a team owner before being tapped to join IndyCar management, he had fielded multi-car teams in 414 races in Indy car, Firestone Indy Lights and Formula BMW, earning six victories and 16 poles.

It's not immediately known whether the other opportunities the septuagenarian mentioned are a return to racing management, or in another motorsports championship, or simply time off to put his feet up after a long, successful and remarkable career in the business.