EXHIBIT A (99.1)

 Sistema

Name	Business Address	Position with Reporting Person and Principal Occupation	Citizenship
Sergei Boev	Mokhovaya Str 13 Moscow 125009 Russian Federation	Deputy Chairman CEO, Joint Stock Company RTI (10, 8 Marta street, Bld. 1, Moscow, Russia, 127083)	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
Patrick Clanwilliam	Mokhovaya Str 13 Moscow 125009 Russian Federation	Independent Director	United Kingdom
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
Peter Mandelson	Mokhovaya Str 13 Moscow 125009 Russian Federation	Independent Director	United Kingdom
Roger Munnings	Mokhovaya Str 13 Moscow 125009 Russian Federation	Independent Director	United Kingdom
Mikhail Shamolin	Mokhovaya Str 13 Moscow 125009 Russian Federation	Director, Chief Executive Officer, Chairman of Management Board	Russian Federation
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
Elena Vitchak	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Head of HR department	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 and Information Technologies Department	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
Valentin Korchunov	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Investment Portfolio Manager	Russian Federation
Mikhail Cherny	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Investment Portfolio Manager	Russian Federation
Artyom Zasursky	Mokhovaya Str 13 Moscow 125009 Russian Federation	Vice President, Head of Strategy	Russian Federation

Sistema Finance

Name	Business Address	Position with Reporting Person and Principal Occupation	Citizenship
Sergei Drozdov	26, avenue Monterey 2163 Luxembourg	Managing Director	Russian Federation
Felix Evtushenkov	26, avenue Monterey 2163 Luxembourg	Director Director, First Vice President, Head of Investment Portfolio, Member of Management Board of Sistema	Russian Federation
David Khidasheli	26, avenue Monterey 2163 Luxembourg	Director	Germany
Yuri Krupitsky	26, avenue Monterey 2163 Luxembourg	Director	Luxembourg
Markus Leninger	26, avenue Monterey 2163 Luxembourg	Director	Austria
Vsevolod Rozanov	26, avenue Monterey 2163 Luxembourg	Director CFO of Sistema	Russian Federation
Mikhail Shamolin	26, avenue Monterey 2163 Luxembourg	Director CEO of Sistema	Russian Federation
Emile Wirtz	26, avenue Monterey 2163 Luxembourg	Managing Director	Luxembourg
Brian Dickie	26, avenue Monterey 2163 Luxembourg	Director	United Kingdom

STA

Name Business Address Position with Reporting Person and
Principal Occupation Citizenship

Natalia Koroleva Mokhovaya Str 13
Moscow 125009
Russian Federation General Director Russian Federation