Although it has had to compete against NBC's Olympics coverage for ad dollars from affluent businesses that can afford to shell out the big bucks, Fox said on Thursday that it had sold out all its ad availabilities for next week's MLB All-Star Game at an average of $550,000 for each 30-second commercial, slightly more than such spots went for a year ago. General Motors' Chevrolet brand will also be sponsoring the pre- and post-game shows. The company recently decided to pull out of next year's Super Bowl telecast. The All-Star Game ordinarily represents the top-rated sports telecast of the summer, with 12 million watching the 2010 game and 11 million the 2011. The Game is scheduled to air next Tuesday, July 10 at 7 30 p.m. ET.