An Italian buyout firm is poised to take a 50% stake in Aston Martin in a deal that values the luxury UK carmaker at £750m, according to a person familiar with the situation.

Investindustrial, which was set up in 1999 and has more than €3bn of assets under management, is close to signing a final agreement to buy the stake from Aston Martin's Kuwaiti owner, The Investment Dar, in the next few 24 hours, the person said. The Investment Dar, a Kuwaiti finance house, will retain the remaining stake. The person said the deal was "almost tied up".