Moscow, Russian Federation — June 15, 2006 — Mobile Telesystems OJSC («MTS» — NYSE: MBT), the largest mobile phone operator in Russia and the CIS, announces the decision made at its Extraordinary Meeting of Shareholders.

On June 14, 2006, the Extraordinary General Meeting of Shareholders (EGM) terminated the powers of the current President and CEO, Mr Vassily Sidorov, and elected Mr Leonid Melamed as the Company’s new President and CEO. Mr Melamed has been the acting President and CEO of MTS since April 14, 2006. Commenting on the appointment, the Chairman of MTS’ Board of Directors (BoD), Sergey Schebetov, said: «We are pleased with the shareholders’ decision to approve Leonid Melamed to the position of President and CEO. As Chairman of the Company’s BoD, I feel that Leonid is the right man for the job given his proven experience as a manager and his leadership skills.»

Biography

Leonid Melamed was born on July 11, 1967 in Moscow. He is a graduate of the Sechenov Moscow Medical Academy and holds a PhD in Medicine.

From February 1992, he served as Director of ROSNO’s Centre for Medical Insurance. In June 1992 he held the position of Deputy Chairman of the Management Board and, from 1993, First Deputy Chairman of the Management Board. From September 1997, he served as First Deputy Director General and, from March 2001, as First Deputy Director General-Executive Director. Mr Melamed held the position of Director General and Chairman of the Management Board of ROSNO from September 15, 2003.

Mr Melamed was appointed by MTS’ BoD to the position of acting President and CEO of MTS on April 14, 2006.

Leonid Melamed is married with two daughters and one son.