Premier Oil plc was an independent UK oil company with gas and oil interests in the United Kingdom, Asia, Africa and Mexico. It was devoted entirely to the 'upstream' sector of the industry — the exploitation of oil and gas — as opposed to the 'downstream' refining and retail sector. It was listed on the London Stock Exchange until it was acquired by Chrysaor Holdings and then merged into Harbour Energy in March 2021.
Sanctioned oligarchs take stake in largest UK oil firm
Petr Aven and Mikhail Fridman become minority shareholders after Harbour Energy buys German firm.
BBC News