FRANKFURT, Feb 21 (Reuters) - Siemens Energy is confident it can solve quality issues at its onshore wind division but that process could take several years, its CEO said in written remarks published ahead of the group's annual general meeting (AGM).

"The losses we incurred in our wind business and the underlying problems are unacceptable. We will not tolerate them," Christian Bruch said. "We are resolutely tackling them and will ultimately solve them."

At the heart of the problem are quality issues with the group's newer generations of onshore wind turbines, the 4.X and 5.X platforms, with Bruch saying that fixing the problems will probably take several years.

Siemens Energy is scheduled to hold its AGM on Feb. 26, with investors expected to slam the group for a share price plunge in the wake of the turbine issues, problems that ultimately led the group to seek billions of euros in state-backed guarantees.

Bruch said that after eight months of intense analysis by an expert task force no new causes of losses had been identified with the two models, meaning a 1.6 billion euro ($1.7 billion) provision set aside to cover the problems was still seen as sufficient.

"We will solve these wind-power problems. We will win back your trust, the trust of our owners," Bruch said.

($1 = 0.9251 euros) (Reporting by Christoph Steitz; Editing by Kirsten Donovan)