One of NASCAR's highest profile drivers Danica Patrick has announced she won't return to Stewart-Haas Racing next year due to a new sponsorship arrangement for the team.

Patrick's comments on her Facebook page came shortly after grocer Smithfield Foods said it would become a primary sponsor at Stewart-Haas in 2018.

"It has been my honour to drive for Tony Stewart, Gene Haas and everyone at Stewart-Haas Racing for the past six seasons," Patrick wrote.

"My time driving for them, however, has come to an end due to a new sponsorship arrangement in 2018."

There had been plenty of speculation that Patrick, who lost her primary sponsor at the start of 2017, would not be able to fulfill sponsorships heading into the 2018 season.

She is now among a number of drivers who have yet to secure a firm contract to drive next season.

Patrick, 35, is still searching for her first top-five finish after five seasons behind the wheel of the No.10 Ford.

"Sponsorship plays a vital role in our sport, and I have been very fortunate over the course of my career, but this year threw us for a curve," Patrick said.

"Right now, my focus is on the remainder of the 2017 season and finishing the year strong. I have the utmost faith in myself and those around me, and feel confident about my future."

Patrick burst onto the scene in May 2005 when she stunned the world by leading for 19 laps to become the first woman to score a top-five finish (fourth) in her first Indianapolis 500.