E.On, Germany's biggest utility company and one of the biggest electricity and gas suppliers to the UK, has posted a massive annual loss for a second year running.
The company said its net loss more than doubled to €6.9 billion in 2015, from €3.16 billion in 2014.
E.On said it had suffered €8.8 billion in writedowns on loss-making power plants that it plans to list separately this year.
E.On also warned that future profits, dividends and cash flows were expected to decline further because conditions continue worsen for legacy power providers as wholesale prices decline and renewable energy capacity rises.
"Our numbers reflect the far-reaching structural transformation that our industry is experiencing and that continues unabated in the current year," Johannes Teyssen, E.On chief executive, said.
"The course ahead will be tougher and longer than anticipated," he warned.
David Cheetham, CFD and FX broker XTB.com, said that E.On's third annual loss and its second in three years will be of concern to investors.
"The change in direction to focus less on traditional power generation techniques continues to weigh on the company's bottom line," Cheetham said.
E.On's results come a day after rival npower cut a fifth of its workforce after what its chief executive Paul Coffey called "extremely disappointing" results.
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