By Andrés González

They have settled on David Mesonero, currently Siemens Gamesa's managing director of corporate development, strategy and integration, as the new CFO.

Siemens, which owns 59 percent of the firm, and Iberdrola, which holds a 8 percent stake, have had a difficult relationship ever since they merged Gamesa and Siemens Wind Power in April 2017, disagreeing on everything from how the business should be run to board appointments.

Since the merger, Siemens Gamesa’s shares have tumbled more than 48 per cent as it repeatedly cut its profit forecasts despite overtaking Danish rival Vestas last year to become the world's biggest wind turbine maker in terms of sold turbine capacity.

The wider industry has suffered from stiff competition and a winding down of state subsidies, but Vestas's shares have fallen by just 24 percent during the same period.

Siemens and Iberdrola will back Mesonero's appointment as new CFO at a board meeting set for October 16, the sources said.

"The fact that Siemens is not blocking the appointment of Mesonero is the proof that both groups have reached a deal after months of clashes," said one of the sources.

Iberdrola and Siemens Gamesa declined to comment. Siemens declined to comment on the appointment but said in an emailed statement it was committed to delivering on the cost savings and growth targets laid out in Siemens Gamesa's strategic plan.

While Mesonero, who is the Iberdrola's chairman's son-in-law, is close to the Spanish utility, he was a strong advocate of the merger between Gamesa and Siemens Wind Power in 2017 and is considered to be a compromise candidate.

Mesonero led the merger talks between Gamesa and Siemens Wind Power and has been in charge of the integration of the two companies.

His appointment was made possible by a deal made by Siemens and Gamesa at the time of the merger that the Spanish power company would have the right from October 3 to name the CFO and Siemens would not oppose it unless there was "material aspects for refusal."

(Reporting by Andres Gonzlaez. Additional reporting by Alexander Huebner; Editing by Julien Toyer and Adrian Croft)

By Andrés González