Uniper (UN01.DE) has already booked billions of euros of losses on derivatives, exacerbating a crisis as it rushed to plug the gap left after Russia turned off the taps.
Like other energy firms, Uniper uses derivatives, such as securing an option to sell gas at a set price in the future, to guard against energy price swings.
"In total, we have derivative positions of about 216 billion euros as of September 30 2022," a spokesperson for Uniper said, adding that the riskier part of this was small.
According to its accounts, Uniper held around 198 billion euros of receivables from derivative instruments as assets.
It is also more than the 131 billion euros Germany's RWE (RWEG.DE) had at the end of June, public data shows.