Moscow, Russian Federation — Mobile TeleSystems OJSC (“MTS” — NYSE: MBT), the leading telecommunications provider in Russia and the CIS, has today filed its annual report on Form 20-F for the fiscal year ended December 31, 2011 with the United States Securities and Exchange Commission.

The document can also be found at https://www.mtsgsm.com/resources/annual_reports/ of the Investor Relations section. Hard copies of the document with the Company’s complete audited financial statements will be available free of charge to shareholders upon request.

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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/