Moscow, Russia – May 17, 2007 – “COMSTAR - United TeleSystems” (“Comstar UTS”) (LSE: CMST), the leading combined telecommunications operator in Moscow and the Moscow region, today announced the appointment of Mladen Pejnovic as Vice President responsible for international business development. Mr. Pejnovic will head the newly created business unit “Comstar International” dealing with the Company’s asset management in and outside the CIS countries.

“Comstar International” is the latest business to be established as a result of creating a new management structure of the Company. Mladen Pejnovic will focus on strengthening the affiliates’ and subsidiaries’ positions abroad, as well as exploring opportunities for acquiring new assets outside Russia.

Mladen Pejnovic was born on May 27, 1953, in Zagreb, Croatia. Previously, he served as Vice President – Director of Transformation Project Office of Golden Telecom, Moscow and First Deputy General Manager of Sovintel, Moscow. From 2002 and to 2005, he was General Director of Golden Telecom, Ukraine. From 2001 to 2002 Mladen Pejnovic served as Senior Vice President of MCT Corporation. From 1997 to 2000, he held several senior positions in companies within the Golden Telecom Holding Inc. From 1995 to 1997, he served as Marketing and Sales Director of Millicom International Cellular. Mladen Pejnovic is a graduate of Zagreb University (Croatia) and holds a degree in Economics.