Catalytic oxidative coupling of methane to higher hydrocarbons is an alternative to conversion of methane to synthesis gas (by steam reforming or partial oxidation) and subsequent reaction of the synthesis gas to produce refinery or petrochemical feedstocks. It was recognized early in the development of oxidative coupling that purely gas phase processes could play an important role in determining the composition of the products. An experimental study in a well characterized jet stirred reactor confirmed earlier results and demonstrated that methane was responsible for the inhibition of C2 oxidation. The experiments in the jet stirred reactor were performed at total pressures of 20-100 Tom, and were successfully modeled with a detailed chemical kinetic model. More recent results have been obtained at somewhat higher pressures, but these are still at considerably lower pressures than would be used in a practical process. However, in view of the likely increased importance of gas-phase reactions at higher pressures, particularly in the conversion of ethane to ethylene and other olefins, a key component of the process concept, and of the success of the model at low pressure, a modeling study of the gas phase processes at higher pressures is justified.