An Astana court upheld a 2.356 trillion tenge ($5 billion) environmental fine against North Caspian Operating Company, the operator of Kazakhstan's Kashagan oil field, whose shareholders include KazMunayGas, Exxon Mobil (XOM), Shell (SHEL), TotalEnergies (TTE), Eni (E), Inpex and China National Petroleum, Bloomberg reported Friday.

Kazakhstan's Ministry of Ecology and Natural Resources told Bloomberg that the April 8 ruling confirmed penalties tied to excessive sulfur storage at the field. The decision has entered into legal force, the report said.

The penalty is tied to a wider $166 billion arbitration dispute over environmental claims and state revenue from the project, the report added. Kashagan remains central to Europe's supply shift away from Russian energy after Russia's invasion of Ukraine, it said.

Exxon Mobil, Shell, TotalEnergies, Eni, Inpex and China National Petroleum did not immediately respond to MT Newswires' request for comment.