The present invention consists of an improved method and apparatus to upgrade bitumen in various forms which comprises four main components; namely, a fractionator equipped with a condenser, a heavy gas oil catalytic treater, a catalyst regenerator/gasifier and a gas cleanup assembly. In operation, the bitumen in liquid form is fed to the fractionator for initial separation of fractions with the bulk of the bitumen leaving the bottom of the fractionator in the form of a heavy gas oil which is pumped to the catalytic treater and sprayed on a hot catalyst to crack the heavy gas oil (an endothermic reaction) to release lighter hydrocarbons in the form of H.sub.2 rich volatile matter while depositing carbon on the catalyst. The volatile matter from the treater is directed to the fractionator where the condensable fractions are separated from the non-condensable H.sub.2 rich gas, a valuable primary gas. The carbon containing catalyst from the treater is recycled to the regenerator/gasifier, and the catalyst after being regenerated (an exothermic reaction) is fed hot to the treater. Various fractions are removed from the fractionator as intermediates in the form of light napthas and light oils. The off-gas from the regenerator/gasifier is directed to a gas cleanup system to produce a valuable secondary gas. Both the primary gas and the secondary gas may be further utilized in the processing of the intermediates produced by the method, the primary gas being a source of H.sub.2 and the secondary gas being a source of thermal energy.