Moscow, Russian Federation – Mobile TeleSystems OJSC (“MTS” – NYSE: MBT), the largest mobile phone operator in Russia and the CIS, announces the launch of 3G networks in Chelyabinsk and Irkutsk, bringing the total count of cities to 10.

Chelyabinsk and Norilsk are the latest additions to the expanding geography of MTS’ 3G networks across the Russian regions. MTS launched the first pan-regional 3G network in Russia in May 2008 in St. Petersburg followed by Sochi, Yekaterinburg and Kazan. In August 2008, MTS expanded its 3G network to Nizhniy Novgorod. In September 2008, the Company brought next-generation networks to Novosibirsk and Norilsk, the two large industrial centers in Siberia, and Vladivostok, the largest city in the Russian Far East.

“We are seeing very strong demand for data services in the regions where 3G networks were launched,” noted Mr. Aleksander Popovskiy, Head of MTS Russia. “For example, in Yekaterinburg we saw mobile Internet traffic grow more than 30% in three months following the launch of the network. We believe that the residents of Chelyabinsk and Irkutsk will also become avid users of our services available on our 3G network.”

MTS intends to launch 3G networks in at least 14 cities during 2008 and in up to 40 cities in Russia through 2009. The Company also holds 3G licenses in Uzbekistan and Armenia, where the networks are scheduled for launch in 2009.

Development of 3G networks is a cornerstone of MTS’ strategy to provide mobile broadband in the CIS. With relatively low levels of fixed-line penetration and historic underinvestment in infrastructure throughout the markets of operation, MTS views its networks as an ideal vehicle to meet the growing broadband Internet needs of subscribers through attractive data products and services.