Qatar Investment Authority (QIA) has joined hands with US private equity firm Carlyle Group to bid for a near 40 per cent stake in Turkish airport operator TAV Havalimanlari Holding, said three sources close to the deal.

French construction group Vinci is also one of the top bidders in the race for the key TAV stake, the sources told Reuters on Friday.

TAV shareholders construction firm Tepe Insaat and Akfen Holding are selling 18 per cent stakes each, they said.

Minority shareholders holding 3.52 per cent of the shares will also sell their stakes in a deal which values the firm at around $2 billion, they added.

'We know that Vinci is leading because TAV shareholders prefer a strategic investor,' said one source, while another said: 'Vinci is leading, but they also talk to others. They also talk to Carlyle and (the) Qatari partnership and they are also very keen.'

A spokesman for Vinci declined to comment.

In a statement issued after the market close, Akfen said the bidding process was underway for the partial or full sale of its TAV stake, but had not reached a point that necessitated saying any more than that.

'The necessary statement will be made if a development emerges that requires us to make such a statement,' it said.

Tepe and Akfen said in September they would evaluate strategic options for their stakes in TAV.

Akfen has a 26.12 per cent holding, according to its web site. Tepe Insaat has 26.06 per cent.

TAV chief executive Sani Sener will keep his 4.03 per cent stake - held through his family construction business Sera Yapi - in the possible deal and the remaining 40.28 percent is freely floating.

TAV is the leading airport operator in Turkey according to 2010 passenger statistics and the largest duty-free operator.

TAV generated 753 million euros in consolidated revenue in 2010. The company runs 10 airports, including Turkey's biggest airport Istanbul Ataturk, and its operations also include ground handling unit Havas, a duty free unit, and catering business BTA.-Reuters