Hit by asset write-down charges worth 36 billion kronor, Sweden's Vattenfall reported a net loss of 28.812 billion kronor in the second quarter of the year, a huge drop from 2.3 billion kronor in the same period in 2014.
The state-owned energy firm, a major provider of electricity in northern Europe, has been struggling to improve profits for several years, suffering from weak demand and plunging electricity prices.
It attributed 17 billion kronor of the total asset write-downs to the same fall in profits which led to a shock announcement earlier this year that it planned to close Ringhals 1 and 2 in south-western Sweden.
It said at the time that the two reactors were too costly to keep in production until 2025 as previously planned.
“This is of course very negative but unfortunately reflects the reality we're living in,” said its chief executive Magnus Hall in a statement on Tuesday morning.
It also wrote down an additional 15 billion kronor on its lignite, or brown coal, assets in Germany.
Earlier this year Vattenfall announced that 1,000 workers were being let go as part of a series of bids to curb losses, including speeding up the sale of the German plants.
It reported a total turnover of 36.1 billion kronor in the second quarter of 2015 on Tuesday, down from 36.6 billion in the same period last year.
Hall said that the work to tighten the belt was continuing “to identify further reductions in costs”.
Many energy providers in Europe have made huge asset write-downs in the last two years because of weak demand for electricity against a background of sluggish economic activity.
They have also been caught out by the US shale energy boom, which has pushed down the price of coal for power generation, undermining the profitability of new gas-powered plants and some investment programmes.
Vattenfall employs more than 30,000 and has operations in Sweden, Finland, Denmark, Germany, the Netherlands and Britain.