Moscow, Russian Federation – November 9, 2005 – Mobile TeleSystems OJSC (“MTS” — NYSE: MBT), the largest mobile phone operator in Russia and the CIS, announces that its consolidated subscriber base reached 52.4 million users on October 31, 2005.

During October 2005, MTS’ consolidated subscriber base increased by 2.07 million subscribers, of which 1.51 million were added in Russia.

Subscribers (mln)	Oct. 31, 2005	Sept. 30, 2005	Growth Subs	Growth %	Oct. 31, 2004	Growth Subs	Growth %
Total consolidated subscribers, end of period	52.43	50.36	2.07	4.1%	27.79	22.79	89.2%
Russia	40.38	38.87	1.51	3.9%	21.64	17.27	86.2%
Moscow and the Moscow region	9.91	9.67	0.24	2.5%	6.83	2.84	43.5%
St. Petersburg and the Leningrad region	2.36	2.32	0.04	1.9%	1.64	0.67	42.9%
Rest of Russia	28.10	26.88	1.22	4.5%	13.17	13.75	115.3%
Ukraine	11.49	10.94	0.55	5.0%	5.89	5.25	99.7%
Uzbekistan	0.51	0.49	0.02	5.5%	0.26	0.22	89.9%
Turkmenistan	0.06	0.06	—	—	—	—	—
MTS Belarus1	1.94	1.85	0.09	4.9%	1.04	0.90	86.4%

1MTS owns a 49% stake in Mobile TeleSystems LLC, a mobile operator in Belarus, which is not consolidated.