Gamesa Corporacion Tecnologica SA confirmed it is in talks about combining wind-energy activities with Siemens AG, a tie-up that would create the world’s largest wind turbine manufacturer. Gamesa and Siemens are in talks on “a potential integration of certain wind energy businesses,” Gamesa said in a regulatory filing Friday, but an agreement hasn’t been reached. The companies late last year agreed in principle to a potential combination of their wind turbine activities, these people said, but it was unclear what structure the combination would have. If Siemens were to acquire Gamesa, the deal would cost the German company around EUR4.6 billion ($5 billion), business advisory firm FTI Intelligence estimated. Any deal would have to be agreed to by Spanish utility Iberdrola SA, Gamesa’s largest shareholder with a 20% stake. The wind turbine industry has faced a recent wave of consolidation. In 2015, Germany’s Nordex SE acquired the renewable energy arm of Spain’s Acciona SA in a EUR785 million deal. As part of that, Acciona now holds a 29.9% stake in Nordex. “Making a move for Gamesa now will propel Siemens to the top of the global turbine market,” FTI said, and bolster the company against growing competition. The combination would create the top wind turbine maker by sales and market share. “Siemens and Gamesa together would have around 15% of the global wind market on current market shares, easily outstripping market leader Vestas SA and General Electric Co.,” FTI said. Siemens’s wind and renewables unit had revenue of EUR5.66 billion in the fiscal year that ended in September. Siemens overall revenue was EUR75.6 billion. Gamesa posted revenue of EUR2.5 billion in the first nine months of last year and forecast full-year sales of up to EUR3.4 billion. An acquisition would also give Siemens exposure to emerging markets where Gamesa has more of a foothold. Still, an acquisition could face obstacles at a time when Siemens shareholders are pushing the company to improve profitability. “Siemens shareholders may be skeptical about paying around EUR4.6 billion upfront to grow a business segment [that] has been perceived to be underperforming on margins compared to its other divisions,” FTI said. A deal with Gamesa would mark Siemens’s second large transaction in January. The Munich-based company earlier this week agreed to buy U.S. simulation software supplier CD-adapco for around $970 million. Since taking the helm in July 2013, Siemens Chief Executive Joe Kaeser has worked on expanding the already-dominant energy business through acquisitions. In 2014, Siemens agreed to buy U.S. oil-equipment maker Dresser-Rand group Inc. for $7.6 billion including debt.