The partial oxidation of methane by oxygen giving synthesis gas can be catalysed to thermodynamic equilibrium using the transition metals Ni, Ru, Rh, Pd, Pt and Ir supported on inert oxides. The yield of CO and H-2 increases with increase in temperature (650 - 1050K) and decreases with increasing pressure from 1 to 20 atm. The gas mixture N2: CH4: O2 at the ratio 4:2:1 at 1050K and 1 atmosphere with a space velocity of 4 x 10(4) hour-1 gives an approximately 92% yield of synthesis gas. Under similar conditions of temperature and pressure we show that catalysts such as iridium on alumina are also active for the combined partial oxidation and carbon dioxide reforming reaction giving synthesis gas in similarly high yield.