Browne told the newspaper he will be appointed executive chairman of L1 Energy on Monday, giving up his jobs at private equity firm Riverstone and UK gas explorer Cuadrilla. The appointment comes as L1 Energy, backed by investment funds owned by Fridman and his partner German Khan, prepares to complete as early as next week a 5 billion euro ($5.60 billion) deal to buy RWE Dea [RWEDE.UL], the oil and gas arm of German utility RWE.