* Media-Saturn restructuring to respond to e-commerce
* Power struggle between owners of company
* Company founder had called for replacement CEO
* Metro regrets departure, names Haas acting replacement (Adds Metro statement, background)
DUESSELDORF, Germany, May 6 (Reuters) - The chief executive of Europe's biggest electronics chain Media-Saturn is to step down after 27 years at the company, saying he did not feel he had the support of all the firm's owners.
The departure of Horst Norberg, who took over as chief executive in 2011 on a contract that runs until the end of 2015, follows a call last month by the company's founder Eric Kellerhals for applications to replace Norberg next year.
Kellerhals, who owns a stake of close to 22 percent in the Media-Saturn, is locked in a battle for control of the company with majority-owner Metro. Kellerhals has frequently clashed with Media-Saturn's management over the running of the retailer, which runs more than 950 stores in 17 countries.
Kellerhals had accused Metro of moving too slowly to find a replacement for Norberg, while Metro has said Kellerhals was "completely unprofessional" to advertise for a new CEO online.
Norberg, 66, said in a statement on Tuesday he doubted he had the full support of the company's owners after the events of recent days.
Norberg, who joined the company in 1987 and served as chief operating officer for a decade from 2001, had last week said that Media-Saturn would restructure its business in response to a rapid shift towards online retailing.
Media-Saturn's move into e-commerce was delayed until 2010 by the long-running dispute between Metro and Kellerhals.
"Media-Saturn is competing in an increasingly difficult market," Norberg said. "I am convinced that we are on the right track with this new strategic and organisational direction. At the same time, the CEO needs the unconditional support of all its owners for this."
Media-Saturn is the world's second biggest consumer electronics chain after Best Buy and competes with Dixons Retail and Darty Plc. Its sales fell 0.7 percent to 6.6 billion euros ($9.16 billion) in the last quarter of 2013, hurt by falling currencies in eastern Europe.
Retail analysts expect another drop for the January to March period when Metro reports results on May 8. Media-Saturn accounts for about a third of Metro's sales.
Metro Chief Executive Olaf Koch said in a separate statement that he was very sorry that Norberg was leaving, adding he had done an exemplary job of making sure Media-Saturn was geared to changing market conditions and customer demands.
Metro said it was putting its management board member Pieter Haas in charge on an acting basis, relieving him of his Metro responsibilities for business innovation and IT.
Haas, 50, was Media-Saturn chief operating officer from 2001 until 2013, when he joined the Metro management board. ($1 = 0.7205 Euros) (Reporting by Emma Thomasson and Matthias Inverardi; Editing by Christoph Steitz and Jane Merriman)