Moscow, Russian Federation — September 05, 2006 — Mobile Telesystems OJSC («MTS» — NYSE: MBT), the largest mobile phone operator in Russia and the CIS, announces that the Board of Directors has approved a share repurchase program.

MTS announces that the Board of Directors has authorized a share repurchase program to allow a recently established wholly owned subsidiary of MTS in Bermuda (MTS Bermuda) to repurchase MTS’ ADRs representing up to 10% of the total number of outstanding shares of MTS, over a period of 12 months until August 31, 2007.

The purchases may be made in the open market or through privately negotiated transactions under certain requirements as stipulated by SEC Rules 10b-18 and 10b5-1, as well as applicable legal requirements and other factors. The program does not obligate MTS and/or MTS Bermuda to acquire a particular number of ADRs, and the program may be suspended or discontinued at MTS’ and/or MTS Bermuda?s discretion. The repurchases could be funded through MTS’ own cash flows, commercial paper program or potentially through existing credit facilities. The execution of the program will depend on an on-going assessment of market conditions, and the program may be extended at any time. As per Russian law, the launch of the program is subject to approval by the Federal Anti-Monopoly Service.

Remarked Leonid Melamed, President and CEO of MTS, «We are committed to improving shareholder value. Our strong financial position, which allows us to fund our capital expenditures, coupled with our abilities to generate positive cash flows, has put us in a position to deliver this return to our shareholders. Our capital structure will remain robust, and MTS will be better positioned to take advantage of future business opportunities.»