Soon-to-be-nationalized gas importer Uniper reported a record 40 billion euro ($39.3 billion) net loss in the first nine months of this year, after Russia stopped its supplies.

It also marks the biggest loss in German corporate history, according to Mark Spoerer, who holds the chair for economic and social history at the University of Regensburg, even dwarfing more recent outliers such as the 25 billion euros Deutsche Telekom disclosed for 2002.

Since the start of the year, shares in Uniper have lost 93 percent of their value, giving it a current market value of 1.1 billion euros, down from 15.2 billion euros on January 3.

"Our half-year numbers already indicated that this has left massive scars in our financial results," Chief Financial Officer Tiina Tuomela said, adding that an agreed stabilization package that will see Germany take over Uniper was currently being finalized.

Uniper said the net loss factored in 10 billion euros of realized losses the company incurred by replacing Russian gas volumes on the spot market at much higher prices.

This caused daily losses of more than 100 million euros when gas prices spiked over the summer. However, losses have come down to less than 10 million per day since the end of October as markets have cooled off, Uniper said.