Debevoise & Plimpton, Legance and Bonelli Erede Pappalardo have taken lead roles on Air France-KLM's purchase of a stake in Alitalia.

The French-Dutch airline beat Lufthansa to buy a 25% stake in the Italian carrier at a much reduced price of €323m (£293m), after last spring's failed €1.5bn (£1.4bn) bid to buy a minority stake.

Italian independent Legance advised Air France-KLM with a team led by corporate finance partners Filippo Troisi and Andrea Fedi. US firm Debevoise & Plimpton's Paris office advised the airline on the French aspects of the deal, led by office co-managing partner Patrick Laporte and international counsel Severine Canarelli.

Slaughter & May ally Bonelli Erede Pappalardo advised Alitalia's owner CAI on the sale of the stake, with a team led by name partner Sergio Erede and M&A partner Giorgio Fantacchiotti.

It is understood that Freshfields Bruckhaus Deringer advised Lufthansa on its failed bid.

The long-running deal will be seen as an important instruction for Legance, which was formed in December 2007 when 85 partners quit Italian firm Gianni Origoni Grippo & Partners.

Troisi said: "Launched 13 months ago, the firm has grown by 50%, from 85 to more than 120 lawyers. We closed the year with results over 30% above our initial budget, so we are coming out of a very exciting year."

News of the deal came on the same day as the relaunch of the Italian carrier by CAI, a consortium of Italian investors, which took over the assets after Alitalia went bankrupt last year.

As previously reported by Legal Week, Italian firms Chiomenti and d'Urso Gatti took the lead roles advising CAI and the Italian Government on efforts to save Alitalia.