For Comcast Corp., the race is on.

The cable giant is expected to announce in Charlotte, N.C., on Wednesday that it will replace Nationwide Insurance as title sponsor of the NASCAR Nationwide Series in a 10-year deal.

The 33-race stock-car series - hugely popular in the Southeast - will be renamed the NASCAR Xfinity Series, making it Xfinity's first national sports sponsorship. Xfinity is the brand for Comcast's cable, Internet, and phone services.

The Nationwide Series exposes younger drivers to race fans while the NASCAR Sprint Cup Series, sponsored by the wireless giant Sprint Corp., showcases Jeff Gordon, Dale Earnhardt Jr., and the other elite drivers.

Tony Stewart - the driver investigated in connection with the death of a fellow racer on a New York racetrack this summer - races in the Sprint Cup. That race was not a NASCAR event, however.

Both series race on the same iconic tracks, such as Dover International Speedway and Talladega Superspeedway.

Though the sport is still watched by millions and one of the top-rated national TV sports franchises, its television ratings have declined this year, partly because of rain delays at high-viewership races and ESPN's fading interest in auto racing, experts say.

Comcast's deal deeply embeds the cable company in the sport. Comcast-owned NBC Sports will share the TV broadcast rights to the Xfinity Series with Fox Sports.

NBC will televise NASCAR races on its broadcast-TV network and 24-hour cable sports channel. The first race of the Xfinity Series will be aired next July from the Daytona International Speedway. The NBC Sports Network launched this February on its cable channel a daily show - NASCAR America - to publicize the sport.

Financial terms for sponsoring the series were unavailable Tuesday, but sports-media trade publications reported this summer that NASCAR was seeking about $25 million a year each for the sponsorship and a marketing commitment. Nationwide Insurance previously announced it would pull its sponsorship.

Several Xfinity Series races will be held on racetracks in Comcast TV markets, including Chicago, Atlanta, and Miami.

bfernandez@phillynews.com

215-854-5897 @bobfernandez1