Swedish energy group Vattenfall made a huge write-down for the second quarter on Tuesday which pushed it into a net loss.
The firm wrote down the value of its assets by 29.7 billion kronor (3.48 billion euros, $4.58 billion).
Most of the writedown arose from the company's operations in the Netherlands, where many observers say it overpaid for its Nuon unit in 2009.
"Vattenfall is affected by the increasingly gloomy market prospects. The company now makes the assessment that the market will not recover in the foreseeable future," it said in a statement.
Vattenfall swung to a 23.707 billion kronor loss in the second quarter, compared with a 874 million net profit in the same period a year ago.
The company said in March it would axe 2,500 jobs by the end of 2014.
The Swedish utility said it would reduce investments and speed up cost cutting measures, raising its target for savings for 2014 to 2.5 billion kronor from 1.5 billion, and setting a new target of two billion kronor for 2015.
Starting next year, the group's operations will be split into one division for the Nordic countries and another one for the rest of Europe.
The new structure "will allow the regions to focus on their respective core issues and will open up opportunities for risk-sharing in Vattenfall's continental operations over time," chief executive Oeystein Loeseth said.