After more than a year-long probe, the European Commission has cleared the final hurdle for General Electric's €12.4bn (£9bn) acquisition of Alstom's power business after it agreed to sell some of the French company's turbine assets to Italian rival Ansaldo Energia.

The deal will bring together two of the world's biggest manufacturers of power plant hardware.

A clutch of law firms won roles on the transaction including Slaughter and May, Weil Gotshal & Manges, Hogan Lovells, Clifford Chance (CC) and Skadden Arps Slate Meagher & Flom.

GE instructed Slaughters to advise on corporate, financing and pensions and employment aspects with a team that included City corporate partners Frances Murphy and Padraig Cronin. Slaughters' best friend network firm in France Bredin Prat also advised on corporate aspects.

It turned to Brussels-based Skadden partner and European antitrust chief Simon Baxter for advice on competition law alongside CC's Tony Reeves in Brussels.

For the GE bid, Alstom instructed a Weil Gotshal team led by Paris-based corporate partner David Aknin, and a Hogan Lovells competition team headed by Brussels partner and antitrust head Jacques Derenne.

Both Alstom and GE said they now expect to finalise the deal as early as possible in the fourth quarter.

Commenting on the process of securing competition clearance, Skadden's Baxter (pictured) says: "Why did it take so long? It was a big case and all eyes were on the deal."

Weil's Aknin adds: "There is more regulation now and this deal shows that the EU will be very vigilant on antitrust aspects creating additional delays."

Baxter supports a statement by EU commissioner for competition Margrethe Vestager earlier this week, in which she highlighted the importance of the case for showing that European companies wanted investment from overseas. 

He comments: "[It shows] Europe is open to business. It was seen as a test case: whether an acquisition of a large European industrial like Alstom could be permitted to proceed."

Another partner close to the deal says that Vestager "went out of her way to say Europe is open to investment", adding: "I think she's an active and vigorous enforcer and I think companies watched closely to see what she would do. She's had a lot of criticism after the Google antitrust case so she's a bit on the defensive."

Last month (27 August), Google rejected a European Commission proposal to change the way it ranks search results after EU regulators accused it of abusing its dominant position by steering European consumers to its own in-house shopping service.

EU regulators are also still investigating whether Google's Android mobile operating system has breached EU antitrust rules by stifling rival mobile operating systems.

Cleary Gottlieb Steen & Hamilton is representing Google on the shopping complaint and the Android case. Allen & Overy is also advising the company on the Android case.

On the complainant's side across both issues, Clifford Chance is representing a consortium with about 15 members called FairSearch, as well as three individual members of the consortium: Oracle, Nokia and Allegro.