August 2004

31.08.2004
Financial Results for the Second Quarter Ended June 30, 2004

Moscow, Russian Federation — August 31, 2004 — Mobile TeleSystems OJSC (“MTS” — NYSE: MBT), the largest mobile phone operator in Russia and the CIS, today announces excellent financial and operating results demonstrated by increased revenues, net income and free cash-flow for the second quarter of 20041.

24.08.2004
MTS Increases Ownership in its Astrakhan and Volgograd Ventures

Moscow, Russian Federation — August 24, 2004 — Mobile TeleSystems OJSC (“MTS” — NYSE: MBT), the largest mobile phone operator in Russia and the CIS, has acquired additional 50% stakes in Astrakhan Mobile and Volgograd Mobile. As a result of these transactions, MTS’ ownership in the companies increases to 100%.

23.08.2004
MTS at the MOTOR SHOW-2004

MTS welcomes you to the MOTOR SHOW-2004 exposition, which is to be held from 25 to 29 August, 2004 at the Expocenter at Krasnaya Presnaya.

16.08.2004
50% Discount to MTS Users!

From August 18, 2004, MTS users will be given a 50% discount on outgoing local and mobile calls or all incoming calls for 12 months. Calls to favorite and low fixed numbers will be cheaper by half price.

09.08.2004
“Who Called?” — Free Service Extended!

MTS will be extending its free “Who Called” service until December 31, 2004.

06.08.2004
MTS Increases Ownership in its Udmurt Subsidiary to 100%

Moscow, Russian Federation — August 6, 2004 — Mobile TeleSystems OJSC (“MTS” — NYSE: MBT), the largest mobile phone operator in Russia and the CIS, has acquired an additional 49% of Digital Network of Udmurtia — 900 (“DNU-900”), increasing its ownership in the company to 100%.

05.08.2004
MTS Announces Subscriber Growth Numbers for July 2004

Moscow, Russian Federation — August 5, 2004 — Mobile TeleSystems OJSC (“MTS” — NYSE: MBT), the largest mobile phone operator in Russia and Ukraine, announces that its consolidated subscriber base reached 24.12 million users on July 31, 2004.

02.08.2004
Summer Contest: “Do You Want to be in a Film?! See STS at 20:00!”

From July 27, 2004 MTS users can take part in the “Do You Want to be in a Film?! See STS at 20:00!” summer contest.

02.08.2004
MTS Completes the Acquisition of a Controlling Stake in Uzdunrobita

Moscow, Russian Federation — August 2, 2004 — Mobile TeleSystems OJSC (“MTS” — NYSE: MBT), the largest mobile phone operator in Russia and Ukraine, announces that a shareholders’ meeting at Uzdunrobita has approved the transfer of a 74% stake in the company to MTS. Completion of the transfer and MTS’ ownership of this stake was registered with the Uzbek authorities on the same day.

Contact investor relations:

+ 7 495 223 20 25 ir@mts.ru

MTS Investor Relations
App for iPad