NASCAR stars Richard and Kyle Petty and the Richard Petty Driving Experience have opted not to become involved in the formation of the new National Sprintcar League.

A news release issued Sunday from the NSL said league officials learned last week that the Pettys would no longer be part of the startup sprint car league.

There was no immediate comment from the Pettys late Monday.

“Sure, we regret that the Richard Petty Driving Experience has decided to withdraw from the new series. They’re good race people and we’ll miss them, but that is the only thing that has changed,” said Steve Kinser, who won his 20th World of Outlaws series title this past season and signed to drive in the NSL in 2006.

“We look forward to forming the kind of relationships between tracks, race teams, drivers, sponsors, and most importantly the fans to carry 410 winged sprint car racing into the next decade.”

In a news release the NSL cited only the “overwhelming demands in getting a start-up series off the ground” as the reason for the Pettys’ departure.

During the September news conference announcing the formation of the NSL, current Nextel Cup champion and sprint car team owner Tony Stewart said this about the Pettys’ involvement:

“We all feel comfortable that with Richard and Kyle involved this is in good hands. If you don’t have that, you might as well not waste your time.”

Stewart was in New York City participating in activities leading up to the Cup series awards banquet Friday and unavailable for comment.

Many questions remain about the new league, including a TV package and agreements with tracks to host events.

“We are acutely aware that the fans want answers now,” said NSL official Brian Healey. “The reality is that starting a major touring series takes a cooperative effort of many sprint car racing’s major players, and sometimes that takes longer than we all want it to take.”