MTS Announces Change to 2006 Reported Financial Results

MOSCOW, RUSSIAN FEDERATION — MAY 30, 2007 — MOBILE TELESYSTEMS OJSC («MTS» — NYSE: MBT), THE LARGEST MOBILE PHONE OPERATOR IN RUSSIA AND THE CIS, ANNOUNCES THAT IT WILL RECORD A CHARGE TO NON-OPERATING EXPENSES FOR THE YEAR ENDED DECEMBER 31, 2006 IN RELATION TO A $170 MILLION PUT OPTION HELD BY NOMIHOLD SECURITIES INC. («NOMIHOLD»).