Moscow, Russian Federation – Mobile TeleSystems OJSC (“MTS” – NYSE: MBT), the leading telecommunications provider in Russia and the CIS, announces that the Moscow City Telephone Network JSC (“MGTS”), a majority-owned subsidiary of MTS, has increased its stake in Intellect Telecom OJSC (“Intellect Telecom”), a research and development subsidiary of JSFC Sistema (“Sistema” – LSE: SSA), from 39.01% to 49.95% following the completion of the registration of the additional shares issuance report with the Federal Financial Markets Service of the Russian Federation.

MGTS acquired the initial 39.01% stake in Intellect Telecom in November 2010. For additional information, please see press release at https://www.mtsgsm.com/news/2010-11-15-28451.