This document summarizes mobile operator market shares in Russia, Moscow, St. Petersburg, and other regions as of December 2010. MTS had the largest share of the overall Russian market at 38.6%, followed by Vimpelcom at 35.5% and MegaFon at 23.9%. In Moscow, MTS had an even higher share of 66.7%, with Vimpelcom at 20.3% and MegaFon at 13%. The top mobile operators added over 1 million subscribers each in Russia during December 2010.