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 |
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
|
