The management of Mobile TeleSystems (MTS) will be holding a conference call to discuss the Company’s First Quarter 2011 Financial and Operating Results on Thursday, May 26, 2011.

Please note that the conference call will start at:

18:00 hrs (Moscow time)
15:00 hrs (London time)
10:00 hrs (US Eastern time)

To take part in the conference call, please dial one of the following telephone numbers and quote either the Company’s name, MTS, or the conference ID, 4442233:

From the US:       + 1 480 629 9751
From the UK:       + 44 207 038 6346
International:        + 44 207 038 6346

The conference call will also be available at: https://www.mtsgsm.com/news/reports/ via audio webcast.

The earnings release will be posted approximately three hours prior to the conference call and the management’s slide presentation will be posted approximately one hour prior to the conference call at: https://www.mtsgsm.com/news/reports/.

A replay of the conference call will be available on the following telephone numbers from May 26 (from approximately 23:00 hrs Moscow time/20:00 hrs London time/15:00 hrs US Eastern time) to June 2, 2011:

From the US:        + 1 303 590 3030        PIN 4442233 #
From the UK:       + 44 207 154 2833      PIN 4442233 #
International:        + 44 207 154 2833      PIN 4442233 #

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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/

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Mobile TeleSystems OJSC ("MTS") is the leading telecommunications group in Russia, Eastern Europe and Central Asia, offering mobile and fixed voice, broadband, pay TV as well as content and entertainment services in one of the world's fastest growing regions. Including its subsidiaries, the Group services over 108.5 million mobile subscribers in Russia, Ukraine, Uzbekistan, Turkmenistan, Armenia and Belarus, a region that boasts a total population of more than 230 million. Since June 2000, MTS' Level 3 ADRs have been listed on the New York Stock Exchange (ticker symbol MBT). Additional information about the MTS Group can be found at www.mtsgsm.com.