EXHIBIT A (99.1)

Sistema

Name	Business Address	Position with Reporting Person and Principal Occupation	Citizenship
Anna Belova	Mokhovaya Str 13 Moscow 125009 Russian Federation	Independent Director	Russian Federation
Sergei Boev	Mokhovaya Str 13 Moscow 125009 Russian Federation	Deputy Chairman	Russian Federation
Andrey Dubovskov	Mokhovaya Str 13 Moscow 125009 Russian Federation	Director President and Chairman of the Management Board of OJSC MTS	Russian Federation
Felix Evtushenkov	Mokhovaya Str 13 Moscow 125009 Russian Federation	Director, First Vice President, Head of Investment Portfolio, Member of Management Board	Russian Federation
Robert Kocharyan	Mokhovaya Str 13 Moscow 125009 Russian Federation	Independent Director, Chairman of the Nomination, Remuneration and Governance Committee	Armenia
Jeannot Krecké	Mokhovaya Str 13 Moscow 125009 Russian Federation	Independent Director	Luxembourg
Roger Munnings	Mokhovaya Str 13 Moscow 125009 Russian Federation	Independent Director,  Chairman of the Audit, Finance and Risk Committee	United Kingdom
Mikhail Shamolin	Mokhovaya Str 13 Moscow 125009 Russian Federation	Director, Chief Executive Officer, Chairman of Management Board	Russian Federation
Dr. Ron Sommer	Mokhovaya Str 13 Moscow 125009 Russian Federation	Director Chairman of the Board of Directors of OJSC MTS	Germany
David Iakobachvili	Mokhovaya Str 13 Moscow 125009 Russian Federation	Independent Director, Chairman of the Investor Relations and Dividend Policy Committee	Sweden

Vsevolod Rozanov	Mokhovaya Str 13 Moscow 125009 Russian Federation	Senior Vice President, Chief Financial Officer	Russian Federation
Ali Uzdenov	Mokhovaya Str 13 Moscow 125009 Russian Federation	Senior Vice President, Head of Investment Portfolio	Russian Federation
Alexander Gorbunov	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Telecommunication Assets	Russian Federation
Leonid Monosov	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Head of Investment Portfolio	Belarus
Oleg Mubarakshin	Mokhovaya Str 13 Moscow 125009 Russian Federation	Senior Vice President, Head of Legal	Russian Federation
Vladimir Shukshin	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice-President, Head of Security	Russian Federation
Evgeniy Chuikov	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice-President, Head of Corporate Communications	Russian Federation
Sergey Shishkin	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Head of Corporate Governance	Russian Federation
Mikhail Cherny	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Head of Investment Portfolio	Russian Federation
Artyom Zasursky	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Head of Strategy	Russian Federation
Artyom Sirazutdinov	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Head of Investment Portfolio	Russian Federation
Alexey Guriev	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Head of HR	Russian Federation

Sistema Finance

Name	Business Address	Position with Reporting Person and Principal Occupation	Citizenship
Brian Dickie	26, avenue Monterey 2163 Luxembourg	Director	United Kingdom

Sergei Drozdov	26, avenue Monterey 2163 Luxembourg	Managing Director	Russian Federation
Felix Evtushenkov	26, avenue Monterey 2163 Luxembourg	Director, Chairman of the Board of Directors Director, First Vice President, Head of Investment Portfolio, Member of Management Board of Sistema	Russian Federation
Yuri Krupitsky	26, avenue Monterey 2163 Luxembourg	Director	Luxembourg
Dr. Wolfram Mörsdorf	26, avenue Monterey 2163 Luxembourg	Director	Germany
Dr. Fritz Oesterle	26, avenue Monterey 2163 Luxembourg	Director	Germany
Vadym Pavlus	26, avenue Monterey 2163 Luxembourg	Director	Ukraine
Emile Wirtz	26, avenue Monterey 2163 Luxembourg	Managing Director	Luxembourg
Artyom Zasursky	26, avenue Monterey 2163 Luxembourg	Director Vice President, Head of Strategy, Member of Management Board of Sistema	Russian Federation

STA

Name	Business Address	Position with Reporting Person and Principal Occupation	Citizenship
Oleg Sidorov	Mokhovaya Str 13 Moscow 125009 Russian Federation	General Director	Russian Federation