Marcus Smith, son of billionaire track owner Bruton Smith, was selected as Humpy Wheeler's successor Wednesday at Lowe's Motor Speedway and Speedway Motorsports Inc.

Marcus Smith takes over as president and CEO of SMI, which owns seven tracks currently on NASCAR's Cup schedule, and president and general manager of Lowe's Motor Speedway.

He replaces Wheeler, who stepped down after 33 years of running LMS last week. Bruton Smith endorsed his 35-year-old son for the jobs, but SMI's board of directors did not make it official until Wednesday afternoon.

"Marcus has been training for this opportunity throughout his professional career," said Bruton Smith, chairman and chief executive officer of Speedway Motorsports. "He's come up through the ranks at Charlotte, proven his business savvy with our most recognizable sponsors and handled our sanction negotiations with NASCAR.

"But the thing that's made Marcus a success and will continue to do so, is that in his heart, he's a race fan. He never loses sight of the fact that our customers are the key to everything we do and he always wants to put our fans first."

Marcus Smith attended the University of North Carolina, where he first studied to be a doctor and later a journalist. But he spent most of his time at LMS, the centerpiece of his father's expanding showcase of speedways.

He started working at the suburban Charlotte track at the lowest levels, picking up trash, selling tickets and souvenirs and even cutting the grass, in summer internships that eventually moved him up the corporate ladder.

Marcus Smith joined LMS as a sales associate in 1996, and was the Manager of New Business Development in 1999. He became vice president of business development for SMI in 2001, and was made a director in 2004. That same year, he became the executive vice president of national sales and marketing for SMI.

He's also a member of the board of managers for SMISC, LLC, an equally owned merchandising joint venture between SMI and International Speedway Corporation.

"This sport is in my blood," Marcus Smith said. "I'm going to bring the same passion to work each day that the race fans bring to the track every week. I'm competitive, and I want to be sure we're doing everything we can to provide a fantastic motorsports experience to our fans."

Forbes magazine estimated Marcus Smith's total compensation in 2007 was $1.402 million and said he owns about $500,000 worth of SMI stock.

Marcus Smith replaces Wheeler, who was hired at LMS in 1975 and became president one year later. Wheeler used a flair for the dramatic and outrageous stunts to promote the speedway and turn it into a premier sports facility.

Under Wheeler's management, the speedway expanded its seating capacity to 167,000 and became the first modern facility to install lights for night racing. The speedway was also the first to offer extensive VIP suites, condominiums, an "all-you-can-eat" grandstand section and extravagant pre-race entertainment.

He was on board in 1995 when Smith went public with SMI, the first motorsports company to trade on the New York Stock Exchange, and Wheeler became president of that company, too.

Now Marcus Smith takes over at a time when the speedway needs a major facelift to glisten the same way SMI's newer properties do. Ticket sales have lagged at LMS, and Smith must find a way to pump life into the nearly 50-year old track.

"We've got the best management team in all of sports, and I look forward to working closely with them as we move forward," Marcus Smith said. "We've got a lot more to accomplish this year, and 2009 will be even better as we celebrate the 50th running of the Coca-Cola 600 at Lowe's Motor Speedway."

(This version CORRECTS UPDATES throughout to ADD quotes. corrects Smith's age to 35)