The Dusseldorf-based firm will make a €2.6 billion ($2.7 billion) payment to the German government in the coming weeks, about €100 million more than previously announced, according to the company.
The increased payment will keep the company in compliance with EU state aid requirements imposed by the European Commission.
The German government, which currently owns almost all of the stock in Uniper, has been required to reduce it stake to a maximum of just over 25% by the end of 2028.
Uniper got into serious financial difficulties in 2022 as Russia sharply reduced, and then fully halted, supplies of gas in response to EU sanctions imposed following the full-scale invasion of Ukraine.
As gas prices skyrocketed, Uniper lost billions of euros as it scrambled to replace the cancelled Russian gas deliveries on the open market.
To prevent Uniper from collapsing, the German government offered a roughly €13.5 billion bailout package – and took a more than 99% ownership stake in Uniper.
Uniper had already made an initial €530 million repayment to the German state at the end of September from funds the company had seized from Russian state-owned gas firm Gazprom in August 2022 after it halted deliveries.