VPC - UNDERVALUED OIL STOCK

What about Centrica or Eon. Didn't they take Kerr McGee assets /Caledonia Oil & Gas respectively in order to secure supplies for customers (not entirely sure on this). If they enter into fixed-priced gas with their production arms, so the production sides do not produce taxable profits, can they avoid the additional tax-take. Would such companies be able to transfer profits from their production subsidiaries to their retail supply business, thus making a buy like VPC more attractive to them than others??