This document summarizes mobile operator and market data for Russia, Moscow, St. Petersburg, Ukraine, and regions of Russia for April 2010. It shows that MTS had the most subscribers in Russia, Moscow, and regions of Russia, while Vimpelcom had the most in St. Petersburg. In Ukraine, Kyivstar had the most subscribers followed by MTS and Astelit. The document also provides subscriber numbers, market shares, and net additions for the top operators in each location.