US-owned MCT Corp has sold its 100% stake in Russian operator Vostok Mobile Volga to an unnamed investor. Vostok Mobile Volga holds controlling stakes in several regional cellcos, including 50% in Saratov Mobile, 70% in Chuvashia Mobile and 60% in Penza Mobile. Saratov Mobile and Chuvashia Mobile launched their GSM-1800 networks in 2004, while Penza Mobile is currently testing its network. According to MCT, Saratov Mobile and Chuvashia Mobile have around 130,000 subscribers between them. The company did not release financial details of its latest stake sale.