Hendrick Motorsports has dropped Kasey Kahne from its NASCAR Cup Series line-up for 2018 with a year remaining on his contract.
Kahne has raced for Hendrick since 2012, in a deal signed two years before that, but went two seasons without a Cup race win prior to his victory at Indianapolis a fortnight ago.
Team owner Rick Hendrick called Kahne "a tremendous team-mate and person" and said he had "worked extremely hard" for the squad.
"He has been totally dedicated to our programme since day one," said Hendrick.
"I've always believed that he's a special talent, and I know he will thrive in the right situation.
"We will do everything we can to finish the season as strong as we can."
Hendrick emphasised that it was still committed to running four Chevrolets next season and said it will announce Kahne's replacement at a later date.
It has already signed Alex Bowman to replace the retiring Dale Earnhardt Jr alongside Jimmie Johnson and Chase Elliott.
Kahne is only 19th in the Cup standings, but is set for a playoff place by virtue of his Indy win.
"I'd like to thank Rick and everyone at Hendrick Motorsports for their hard work and dedication, along with providing me a great opportunity and success over the last six years," said the 37-year-old.
"We won six races together and I'm coming off one of the biggest wins of my career at the Brickyard, which has given the #5 team a lot of momentum heading into the playoffs.
"We still have a lot of racing left in 2017 and finishing strong is our top priority.
"I look forward to what the next chapter in my career holds."
Kahne is the latest in a string of Cup veterans to become free agents in recent weeks.
Joe Gibbs Racing has replaced 2003 champion Matt Kenseth with Erik Jones for next season, while Stewart-Haas Racing has not taken up its option on '04 title winner Kurt Busch's 2018 contract.