For an average family of four, a 2-cent levy per kWh would amount to additional costs of around 400 euros annually. At 3 cents, the annual costs would amount to around 600 euros.

Trading Hub Europe, Germany's gas market operator, is expected to announce the cost of the levy later Monday, which is meant to help Uniper and other importers cope with soaring prices due to reduced Russian supply.

Germany's cabinet on Aug. 4 agreed to impose the levy from October 2022 to April 2024.

It aims to share 90% of importers' additional costs of replacing a shortage of gas from Russia among both households and industrial consumers.

(Reporting by Markus Wacket; Writing by Rachel More; Editing by Paul Carrel and Maria Sheahan)