London - A Qatari investment group has agreed to buy Italian fashion house Valentino for an undisclosed sum, the London-based private equity form which controls the luxury label said on Thursday.

"Mayhoola for Investments SPC, an investment vehicle backed by a major private investor group from Qatar, has agreed to acquire Valentino Fashion Group SpA," Permira said in a statement.

Permira did not disclose the identity of the buyer or the price tag but British media recently reported that Qatar's royal family was in talks to buy the label for about £550-600 million (S$1.08-1.18 million).

Valentino chief executive Stefano Sassi said he was "delighted".

"During the past few years, despite swings in the luxury markets, the company has operated with great intensity and remained focused on maximising the potential of the Valentino brand.

"This effort should drive a 60-per cent increase in revenues from 2009 to 2012. Our new shareholder will help us to reach our full potential," he said.

A brand favoured by Hollywood actresses, Valentino was founded by Paris-trained Valentino Garavani in Rome in 1960 and won international fame early on when he designed the wedding dress for Jacqueline Onassis in 1968.

More recent fans include Jennifer Aniston, Keira Knightley and Cameron Diaz.

The fashion house said on its website that it now operates in more than 70 countries with 1,250 points of sale including 66 that are directly managed.

The company had a turnover of 322.4 million euros in 2011.

The 80-year-old Valentino has now retired although he still makes frequent appearances on the global celebrity circuit. The fashion house's current creative directors are Maria Grazia Chiuri and Pierpaolo Piccioli.