The traditional British men's clothing and accessories company, which has featured rugby star Jonny Wilkinson (pictured) in its ads, was acquired for an undisclosed sum.
However, the purchase price has been estimated at about£15 million.
The acquirer, Torreal, also owns a stake in Pepe Jeans.
Commentators suggested that Hackett did not fit well within the Richemont portfolio, which includes luxury goods brands such as Cartier, Van Cleef & Arpels, Alfred Dunhill, Montblanc and Lancel and several premium watch brands, including Jaeger-LeCoultre. It also holds an 18.3 per cent interest in British American Tobacco.
Hackett founders Jeremy Hackett and Ashley Lloyd-Jennings opened their first store on the New Kings Road in London in 1983. Hackett is sold through standalone stores and concessions at Selfridges and Harvey Nichols in the UK, and El Corte Ingles in Spain.