LONDON, United Kingdom —British petrochemicals company Ineos is buying fashion brand Belstaff, best known for its waxed cotton motorcycle jackets once worn by Steve McQueen, in the latest off-beat project by Ineos's billionaire founder Jim Ratcliffe.

Ineos, which claims to be Britain's largest private company, announced the acquisition on Monday, without disclosing its price or strategic plans.

Last month Ratcliffe said he was seeking government support for production of a new 4x4 vehicle modelled on Land Rover's classic Defender, which was discontinued in 2016 after 68 years.

Founded in 1924 in England, Belstaff claims an illustrious line of customers for its motorcycle jackets, including pioneer British aviator Amy Johnson, Lawrence of Arabia and Che Guevara, as well as Steve McQueen. More recently, football star David Beckham has been a promoter of the brand.

"This very British heritage brand, with links to automotive, returns back to British ownership," Ineos said in a statement. Details on its plans for Belstaff will be announced in due course, it said.

The deal is expected to close in the fourth quarter.

Belstaff's current owner is JAB Holding, a consumer goods-focused investment firm backed by the billionaire Reimann family. JAB has been selling off its luxury brands to concentrate on its coffee, restaurants and beauty products with a portfolio of brands that includes Panera, Krispy Kreme and Keurig, as well as a large stake in Coty .

In July, JAB announced the sale of designer shoes company Jimmy Choo to Michael Kors and is also in the process of selling fashion brand Bally.

By Susanna Twidale; Editor: Greg Mahlich.