A Siemens Energy spokesperson declined to comment.

Siemens Energy in May announced plans to bid 4.05 billion euros ($3.93 billion) for the remaining third of Siemens Gamesa it does not already own, hoping to get a better handle on ongoing problems at the wind turbine maker.

It is not uncommon for CEOs to take on the position of chairman at majority-owned subsidiaries that are listed on the stock exchange.

Examples include the CEO of Fortum, who serves as chairman of Germany's Uniper, which is still 78%-owned by the Finnish utility until a nationalisation by the German government becomes effective.

($1 = 1.0309 euros)

(Writing by Rachel More and Christoph Steitz, editing by Kirsti Knolle and Miranda Murray)