The former Cup Series champion had been considering an extension since late last year and decided this week to continue driving the famed No. 43 Dodge.
The person spoke to the AP on condition of anonymity Saturday because portions of the deal, including sponsorship, are still being completed.
Labonte, who starts 39th in Saturday night's race at Richmond International Raceway, was not immediately available for comment.
David Hovis, a spokesman for Petty Enterprises, said the team had nothing to announce Saturday about Labonte's future.
"We still remain 100 percent convinced that Bobby will be with Petty Enterprises next season," Hovis said.
There's been high interest in Labonte's future, especially since Richard Childress Racing announced last month that he'll expand to four cars next season. As the 2000 series champion, Labonte carries a provisional that would help the car make the field at the start of the season.
It became an even better fit when General Mills, sponsor of Labonte's car, was moving its financial backing to the Childress ride.
But Labonte chose not to discuss his future during the past month of speculation.
"I'm very humbled by the level of interest in my future," he said last month. "Moving forward, I'm going to work hard each week to win races. I want to do the best I can for Petty Enterprises and everyone who puts great cars under me each week. That's our focus, and that's what I feel is the right thing to do for all our partners.
"At this time, I have no intention to talk about my plans after 2008 because of the immediate tasks at hand."
Labonte left Joe Gibbs Racing, where he won 21 races and his championship, for a fresh start at Petty Enterprises in 2006 after his performance had talked off with Gibbs. He's scored 11 top-10 finishes since, but is still searching for his first win in the car Richard Petty piloted to seven Cup titles.
But he's remained committed to the rebuilding effort at Petty, and team vice president Robbie Loomis has insisted that Labonte's desire to be part of the turnaround would keep him with the company.
"He came here to take the 43 back to Victory Lane, and I am still confident he wants to do that," Loomis said earlier this week. "It would surprise me very, very much if Bobby left Petty Enterprises."
The team still needs to replace General Mills, which is leaving at the end of the year after nine seasons on the car. It's just the second time the team has had to look for sponsorship of the car Petty drove to 200 victories.
Petty Enterprises is also searching for a business partner, and Loomis has said the company is close to finalizing a deal. The potential partner is believed to be Medallion Financial Group.
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