Moscow, Russian Federation — January 17, 2007 — Mobile Telesystems OJSC («MTS» — NYSE: MBT), the largest mobile phone operator in Russia and the CIS, announces that it has appointed a new Chief Marketing Officer (CMO), Mrs. Cynthia Gordon.

Mrs. Gordon has 15 years of experience in key marketing positions in the largest telecommunications companies. Prior to joining MTS, she held the position of Vice-President in business marketing at Orange for three years and served on business boards of Orange and its mother company France Telecom. From 2001-2003, Mrs. Gordon worked as the marketing director of Orange in the United Kingdom. She also has experience of working at fixed-line (British Telecom) and broadband Internet companies (Demon/Scottish Telecom).

Mr. Grzegorz Esz, the Company's CMO since October 2005, is leaving MTS due to family reasons that require him to return to his native Poland. He will continue to work with the Company as an advisor to the President of MTS on a range of matters.

Mr. Leonid Melamed, President and CEO of MTS, noted: «Grzegorz headed MTS? marketing at a very important period of time for the Company — the introduction of a new brand and of a new marketing strategy in light of a maturing home market. The fact that MTS was able to supersede the expectations of our subscribers and shareholders in 2006 is largely attributable to the marketing department, and we are indebted to Grzegorz for his contribution to MTS success. Cynthia possesses unique for Russia experience in marketing in so far as the understanding of the correlation between national and global aspects of the telecommunications market, as well as implementing the most effective methods to achieve synergy of different types of telecommunications. This experience will be of great use for the Company in the coming years.»

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Biographies

Mrs. Cynthia Gordon graduated with a B.A. in Business Studies from Brighton University. She has 15 years of experience in the telecommunications industry and 20 years of experience in consumer and business marketing. Prior to joining MTS, from 2003 to present Mrs. Gordon was Vice-President of Business Marketing at Orange. She also worked at Orange, United Kingdom, as a marketing director from 2001 to 2003, at Demon/Scottish Telecom as a marketing director from 2000 to 2001, at ACC International (AT&T) as a marketing director from 1998 to 1999, British Telecom as head of ChargeCard and a range of senior marketing positions from 1993 to 1998, at One to One (T-Mobile) from 1991 to 1993, at Lloyds TSB and Abbey National from 1989 to 1993. Mrs. Gordon started her career at Unilever on a management trainee scheme with brand management of major mass-market brands. She is a Freeman of the City of London and a Member of the Worshipful Company of Marketors. Married, has a son.

Mr. Grzegorz Eszwas born in 1972. He is a graduate of the Warsaw University of Technology and the London Business School (London Executive MBA). Mr. Esz has worked in the IT and Telecommunications fields for eleven years and has received awards for his innovations and creative solutions (i.e. Cannes «Golden Lion»). Prior to joining MTS, Mr. Esz worked as a Managing Director for a Retail Division in the second largest Polish Bank (Bank BPH- member of CA-IB Group). Prior to that he worked as the Deputy Chief Marketing Officer at ERA (T-Mobile Company), the largest GSM operator in Poland. Joined MTS in October 2005.