In the method of the invention the catalyst may be used at a concentration of from 1 to 500ppm by weight based on the total weight of the organosilicon compounds. Preferably from 5 to 150ppm by weight are used, most preferably from 5 to 50. The amount of catalyst used in the method of the invention may be reduced when the temperature at which the organosilicon compounds and the catalyst are contacted is increased. The method of the invention may conveniently be carried out at room temperature. The temperature may also be as high as 250° C. Preferably, however, the temperature range is from 20 to 150° C., most preferably from 50 to 120° C.