CHARLOTTE, N.C. (AP) -- Tony Stewart is apparently testing the free agent market, in search of a deal that likely would make the two-time champion NASCAR's highest paid driver. But it also could drive him out of Joe Gibbs Racing.

Stewart's current deal with JGR runs through 2009, and he said last summer he was interested in signing an extension with the team he's driven for since 1998. But contract talks moved slowly, with Stewart saying in January he was in no rush to get a deal done.

Then came a pair of Internet reports alleging Stewart is in negotiations to purchase at least a portion of Haas CNC Racing in a deal that would require him to leave JGR. ESPN.com reports Stewart had asked to be released from his contract at the end of last season.

JGR president J.D. Gibbs indicates the team intends to hold Stewart to his contract.

Stewart is winless this season and tied for sixth in the Sprint Cup Series. In nine full seasons with Gibbs, he's won 32 career Cup races, championships in 2002 and 2005 and more than 67 million dollars in prize money.

(Copyright 2008 by The Associated Press. All Rights Reserved.)