MADRID/FRANKFURT (Reuters) - A deal to merge the wind power assets of Spain's Gamesa GAM.MC and Germany's Siemens (SIEGn.DE) has stalled while French group Areva (AREVA.PA), involved in an existing venture with Gamesa, decides its response to the plan, sources with knowledge of the matter said.
Gamesa and Siemens said in January they were in talks over a possible merger that would create the world's biggest wind power business and bolster the German engineer's weak position in the onshore market.
But the announcement left unanswered the question of how it would affect the Adwen 50-50 joint venture between French state-owned Areva and Gamesa in designing, making and installing offshore wind turbines.
One source said Areva had not decided whether to sell its stake in Adwen to the potential Gamesa-Siemens wind unit, or offer to buy Gamesa's stake as part of a plan to create a French offshore wind energy champion.
"The deal is only on hold because of Areva," a source close to Siemens said. "Everything else is a done deal, including the agreement with the regulator on not having to make a full takeover bid."
Siemens and Gamesa declined to comment. The statement issued in March 2015 announcing Adwen's formation did not say if either party had any preemptive rights to buy out the remaining stake.
Areva said it was closely monitoring developments in the wind power sector and was particularly careful to protect its clients' interests and stick to its commitments.
"We remain focused on carrying out our projects, via our Adwen joint venture," the company said in an emailed statement, pointing in particular to 600 megawatts of installed capacity in the German section of the North Sea, and the future Wikinger project.
The combined group to be formed by Siemens and Gamesa would overtake Denmark's Vestas (VWS.CO) as the world's biggest wind turbine manufacturer by market share.
Siemens has had mixed fortunes with wind power and renewables. In its first quarter through December, orders were up 44 percent, but profit fell 37 percent to 51 million euros ($55 million).
Additional reporting by Georgina Prodhan and Jose Elias Rodriguez; Writing by Sonya Dowsett and Angus Berwick; Editing by Julien Toyer and David Holmes