Moscow, Russian Federation – Mobile TeleSystems OJSC (“MTS” or "the Company" – NYSE: MBT), the leading telecommunications provider in Russia and the CIS, announces a change in the coupon rate of the series 04 ruble-denominated bond ("the bond") from an annual rate of 16.75% to 7.6%.

As the bond carries a two-year put option, bondholders are entitled to a repurchase of their respective securities by the Company. Delivery instructions can be submitted from May 13, 2011 till May 17, 2011. The repurchase is scheduled for May 19, 2011.

Gazprombank, the Lead Arranger of the bond, will act as the Repurchase Agent.

The RUB 15 billion series 04 ruble-denominated bond with maturity on May 13, 2014 and a two-year put option was issued on May 19, 2009. The coupon was to be paid annually at the rate of 16.75%. The bond was included in the "A1" quotation list on the Moscow Interbank Currency Exchange in April 2010.

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For further information, please contact in Moscow:

Joshua B. Tulgan
Director, Investor Relations
Acting Director, Corporate Finance

Department of Investor Relations
Mobile TeleSystems OJSC
Tel: +7 495 223 2025
E-mail: ir@mts.ru

Learn more about MTS. Visit the official blog of the Investor Relations Department at www.mtsgsm.com/blog/