Selective, direct oxidation of methane into useful chemicals remains a big challenge in catalysis in the 21st century. The study presents a new and efficient method based on methane esterification and further hydrolysis to methanol. A platinum-catalyzed system using oleum as the reaction medium for the oxidation of methane to methyl bisulfate in the temperature range between 140 and 180 degrees C at methane pressure 3.0-6.8 MPa has been studied. Analyzing the relationship between the ester concentration and the methane partial pressure, the sulfur trioxide concentration and the temperature, leads to a well-defined equation describing the reaction rate. This equation is applicable for the estimation of the reaction rate and the ester concentration in any moment up to a process time of 22 h. An apparent activation energy is also calculated. (c) 2006 Elsevier B.V. All rights reserved.