ADIL E-ON Marathon Shell
  BP ERT Marubeni Silverstone
  Centrica ExxonMobil Monitor Offshore Sterling
  CH4 Faroe Murphy Talisman
  Chevron First Oil  Nippon Oil TAQA
  Cieco Hardman Noble  Tullow
  CNR Helix North Sea Energy UKOG
  Cultus Hess Oryx Unocal
  Dana Intrepid Energy  Paladin Venture
  DNO IOC Petro-Canada Vienco
  EDP Iona Petrofac
  ENI Ithaca Petro-Summit
  ENS Kerr-McGee Premier
  Enterprise Lundin RWE