PARIS, July 3 (Reuters) - The deal under which the French government will acquire up to 20 percent of Alstom from the engineering company's top shareholder Bouygues amounts to concerted action, French market regulator AMF said on Thursday, a decision that could make it more costly for the state to acquire the holding.
The roughly 2 billion euro ($2.7 billion) acquisition by the French state is part of a multi-party agreement under which U.S. company General Electric will acquire some of Alstom's power turbine assets.
Under a so-called "concert party" arrangement, two shareholders can be seen as acting as one. Bouygues holds 29.3 percent of Alstom - close to the 30 percent at which a shareholder is obliged to make a full offer for the whole company.
During the period in which it plans to acquire the stake, the government had hoped to possibly also acquire some stock on the market at a lower price than that agreed with Bouygues.
In an interview on French radio just ahead of the AMF decision, David Azema, the head of French state holding company APE, said such a decision would not prevent the state from acquiring the 20 percent.
He said it would simply mean that the government would be able to buy "little or nothing" on the market.
($1 = 0.7331 Euros) (Reporting by Jean Michel-Belot and Andrew Callus; Editing by Maya Nikolaeva)