MTS Launches Voluntary Tender Offer for up to 9% of Comstar Shares

MOSCOW, July 13, 2010 - Mobile TeleSystems OJSC ("MTS" - NYSE: MBT), the leading
telecommunications provider in Russia and the CIS, announces that it has
today submitted documentation to COMSTAR - United TeleSystems JSC ("Comstar"
- LSE: CMST), a leading supplier of integrated telecommunication solutions in
Russia and the CIS, regarding the MTS Voluntary Tender Offer ("VTO") to
acquire up to 37,614,678 Comstar ordinary shares that MTS does not already
own for RUR 220.0 per Comstar share. The number of ordinary shares is
equivalent to 9.0% of Comstar's issued share capital, and includes shares
underlying Comstar Global Depositary Receipts ("GDR"s). The launch of the VTO
follows the announcement on June 25, 2010 that the Boards of Directors of MTS
and Comstar had approved and recommended the merger of MTS and Comstar. The
VTO documentation was then filed with the Federal Service for Financial
Markets ("FSFM"), which has now completed its statutory review. MTS currently
owns 61.97% of Comstar, or 64.03% when excluding treasury shares, and
consolidates Comstar in its financial results.

As announced on June 25, 2010, the implied VTO price per
Comstar GDR of USD 7.16[1] represents a 13.1% premium to the three month
volume-weighted average trading price of the Comstar GDR on the London Stock
Exchange up to the close of trading on June 22, 2010.

The Comstar Board of Directors will now review the VTO
documentation and decide upon its recommendation to Comstar shareholders
regarding the VTO. Comstar will then deliver the documentation, together
with its Board of Directors' recommendation, to Comstar ordinary shareholders
and, in the case of Comstar GDR holders, via Deutsche Bank (the depositary
bank for Comstar's GDR facility). Comstar shareholders who subscribe to the
VTO will receive a pro rata cash allocation in the event of
over-subscription. The VTO period commences from the moment Comstar received
the voluntary offer and will remain open until the end of day on September
21, 2010.

MTS has sufficient available cash, cash equivalents and undrawn financing
commitments to purchase the shares in the VTO and has further received a bank
guarantee in this respect from Sberbank, as required by the applicable rules
regarding VTOs.

Mikhail Shamolin, President and Chief Executive Officer of
MTS, commented: "The VTO is part of the overall transaction to merge Comstar
into MTS, and we believe that the VTO provides Comstar minority shareholders
with an attractive liquidity opportunity at a premium to the average historic
trading price of Comstar stock".

"The merger will create the largest integrated
telecommunications provider in Russia and the CIS, and we believe that the
full integration will accelerate the delivery of our '3i' strategic goal of
realizing growth through increasing customer value by providing our customers
with a broad, innovative and bundled offering of mobile and fixed line
telephony, high-speed broadband internet access and television services. Not
only is this expected to further enhance our competitive position, but it is
also expected to streamline our common business processes and further
optimize our combined operating and capital expenditure programmes."

Goldman Sachs International is acting as financial advisor to
MTS and Latham & Watkins LLP is acting as legal advisor to MTS.

Documentation regarding the MTS Voluntary Tender Offer to
acquire Comstar shares is available here: www.mtsgsm.com/merger/

[1] Based on the RUR/USD exchange rate of RUR 30.7267 per USD 1 as of
June 22, 2010.

Learn more about MTS. Visit the official blog of the Investor Relations
Department at www.mtsgsm.com/blog/

Important Information

This press release is not for release, publication or
distribution, in whole or in part, in, into or from any jurisdiction where to
do so would constitute a violation of the relevant laws of that jurisdiction.

This press release is for informational purposes and shall not
constitute an offer to purchase or a solicitation of an offer to purchase
with respect to any securities. Any such offer or solicitation will be made
only by means of the offer document delivered to Comstar.

The final terms of the VTO will be contained in the offer
document delivered to Comstar, which will provide it to Comstar shareholders.
Investors and shareholders in Comstar are strongly advised to read the offer
document and related materials as soon as they have been published, as these
will contain important information. In considering the VTO, Comstar security
holders should rely only on the information contained in the offer document.

This communication is directed only at (i) persons who are
outside the United Kingdom or (ii) persons who have professional experience
in matters relating to investments falling within Article 19(5) of the
Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (the
"Order") and (iii) high net worth entities, and other persons to whom it may
lawfully be communicated, falling within Article 49(2) (a) to (d) of the
Order (all such persons together being referred to as "relevant persons").
Any investment activity to which this communication relates will only be
available to and will only be engaged with, relevant persons. Any person who
is not a relevant person should not act or rely on this document or any of
its contents.

Comstar is a company organized under the laws of the Russian
Federation. The VTO is made to all shareholders, including with respect to
the shares underlying the GDRs, of Comstar and is made solely pursuant to
Russian law and in compliance with the applicable provisions of Section 14(e)
of the Securities Exchange Act of 1934 (the "Exchange Act"), and Regulation
14E thereunder. The Offer is not made or intended to be made pursuant to the
provisions of any other law. Accordingly, MTS and the persons acting in
conjunction with MTS will not procure any further registrations,
authorizations or approvals of the offer document or the VTO by any security
supervisory authority or similar institutions. The Offer will be made in the
United States by MTS and no one else. The Offer will be subject to disclosure
and procedure requirements of Russia which are different from those of the
United States.

MTS, certain affiliated companies and the nominees or brokers
(acting as agents) may make certain purchases of, or arrangements to
purchase, shares in Comstar outside the VTO during the period in which the
VTO remains open for acceptance. If such purchases or arrangements to
purchase are made they will be made outside the United States and will comply
with applicable law, including the Exchange Act.

The release, publication or distribution of this press release
and any other applicable VTO-related documentation in jurisdictions other
than Russia, the UK or the US may be affected by the laws or regulations of
relevant jurisdictions. Therefore, any persons who are subject to the laws
and regulations of any jurisdiction other than Russia, the UK or the US
should inform themselves of and observe any applicable requirements.

FORWARD-LOOKING STATEMENTS

This press release contains certain forward-looking
statements. Such statements may include, but are not limited to, statements
about the benefits of the VTO, expected future earnings, revenues, cost
savings, operations, business trends and other such statements that are not
historical facts, which are or may be based on MTS' plans, estimates and
projections. These forward-looking statements involve risks and
uncertainties, many of which are beyond the control of MTS, that could cause
MTS' actual results to differ materially from those indicated in any such
forward-looking statements. Such statements can be identified, in particular,
by terms such as "will", "expects", "believes", "is of the opinion",
"attempts", "estimates", "intends", "assumes", "plans" and "endeavours" and
similar expressions as they relate to MTS. Such statements are an expression
of MTS' intentions, views or current expectations with regard to potential
future events. They are subject to numerous risks and uncertainties which as
a rule are not within MTS' sphere of control. Certain factors that could
affect MTS' intentions, views or current expectations with regard to
potential future events are discussed more fully in MTS' filings with the
U.S. Securities and Exchange Commission, including but not limited to MTS'
Annual Report on Form 20-F for 2009. It should be noted that the
forward-looking statements contained herein may prove to be incorrect and
future events and developments may differ materially from the forward-looking
statements. MTS undertakes no obligation to publicly update or revise any
forward looking statements whether as a result of new information, future
events or otherwise, except as is required by law.

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 103.5 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.

    For further information, please visit www.mtsgsm.com or contact:
    Joshua B. Tulgan
    Director, Investor Relations / Acting Director, Corporate Finance
    Mob: +7-985-220-4208

    Mobile TeleSystems OJSC
    Tel: +7-495-223-2025
    E-mail: ir@mts.ru

For further information, please contact:Joshua B. Tulgan, Director, Investor Relations / Acting Director, Corporate Finance, Mob: +7-985-220-4208; Mobile TeleSystems OJSC,
Tel: +7-495-223-2025, E-mail: ir at mts.ru