Fox television network begins selling commercial time for the 2012-2013 season. ABC, CBS, NBC and CW are in negotiations Fox Broadcasting has begun selling commercial time for the upcoming television season, kicking off the networks' annual springtime bazaar. The News Corp.-owned network -- which last week finished the regular TV season in first place for the eighth consecutive year in marketers' preferred demographic of viewers ages 18 to 49 -- has accepted advertising orders from movie studios and car companies for the upcoming season, an executive familiar with the discussions said Thursday. Those big-spending advertisers traditionally lead the market by agreeing to pay higher rates in exchange for locking in chunks of commercial time for specific dates, such as the launch of a big-budget movie or rollout of a new car model. VIDEO: Fall TV previews Fox finished the regular TV season with ratings down 9% in the 18-to-49-year-old demographic. Still, the network was able to boast that it also finished first among viewers 18-34 and teens -- giving it an edge in its negotiations with advertisers. The network is attempting to extract slightly higher rates for its 30-second spots compared with last year. The annual upfront market -- which earned its name because networks sell about 80% of their commercial inventory in advance, or "upfront," of the new TV season -- will be closely watched by advertisers and Wall Street. The major networks are expected to amass prime-time commitments worth about $9.2 billion -- roughly on pace with last year's total. Media companies hope the upfront market will once again demonstrate the continued dominance of the major networks and their ability to maintain premium ad rates. Still, the television networks are grappling with challenges, including lower ratings, the increased use of digital video recorders, which allow consumers to fast-forward through commercials, and the introduction of a controversial ad-skipping offering by Dish Network called AutoHop. The networks also are trying to ward off the flight of ad dollars to lower-cost options on the Internet. "TV is still the most effective medium out there in terms of reach and when you are launching a new product," said Greg Kahn, an executive vice president at the ad-buying firm Optimedia. Two weeks ago, Fox unveiled its new prime-time schedule to advertisers in New York. It featured a new sitcom, "The Mindy Project,"starring Mindy Kaling of NBC's"The Office" and a new drama called "The Mob Doctor," featuring Jordana Spiro, who plays a physician who becomes the in-house medic for the Chicago mob. Walt Disney Co.-owned ABC also has started selling its time, according to two people familiar with the negotiations. CBS, NBC and the CW are in active negotiations, other executives said. Fall TV: Fox looks to laughs to boost ratings TV networks desperately seek younger viewers Networks' fight with Dish over ad-skipping has huge implications