Mobile Telesystems OJSC (NYSE:MBT) agreed to acquire the remaining 45.71% stake in OAO Teleservice(Voronezh) on December 19, 2013. The Board of Directors of Mobile Telesystems OJSC have approved the transaction. As on May 8, 2014, Russia's Federal Antimonopoly Service has approved the acquisition of remaining 45.71% stake in OAO Teleservice(Voronezh) by Mobile Telesystems OJSC.