Mobile Content Russia

Moscow, Russian Federation - Mobile TeleSystems OJSC ("MTS" - NYSE: MBT), the largest mobile phone operator in Russia and the CIS, announces that Moodys Investors Service has upgraded the corporate family and existing bond ratings of MTS to Ba2 from Ba3. The outlook on the ratings is positive.

In a press release circulated today, Moodys remarks: "The upgrade reflects (i) the company robust operational and financial performance in the second half of 2006 and six months of 2007; (ii) its demonstrated ability to sustain its market share in Russia, strong positions in Ukraine and a number of other CIS countries; (iii) free cash flow generation in the first half of 2007; (iv) significantly improved profitability metrics, (v) modest leverage below 1.0x Total Adjusted Debt to reported EBITDA on an annualized six months basis, (vi) a relatively conservative and consistent management strategy as regards acquisition activities; and (vii) a higher level of predictability in the company's financial policies over the past 12 months". In addition, Moodys added, "Given the positive outlook, a future upgrade remains a strong possibility."

Please refer to http://www.moodys.com for additional information.