The agreement to create a €9.3bn ($10.7bn) annual revenue combined business was on Friday hailed by the CEOs of both companies as a "perfect fit" that offers an enlarged, Siemens-controlled Gamesa big opportunities for growth onshore, plus the offshore wind clout of the German group's established market-leading operation.

But some of the key premises of the deal were questioned by analysts at Barclays Capital, who wrote that the backlog of the combined onshore business will be well short of Denmark's Vestas in scale – €5.3bn