FIRST QUARTER 2015 FINANCIAL RESULTS UNDER IFRS TO BE RELEASED

ON MAY 13, 2015

ATHENS, Greece – April 21, 2015 –Hellenic Telecommunications Organization SA (ASE: HTO, OTC MARKET:HLTOY), the Greek full-service telecommunications provider, announces that it will release its first quarter 2015 results under IFRS on Wednesday, May 13, 2015, before the opening of the Athens Stock Exchange.

OTE's management will host a conference call at 17:00 (GREECE) / 16:00 (CONTINENT) / 15:00 (UK) /10:00 (EASTERN US) following the release, to review the results.

Details regarding the conference call dial-in and replay numbers as well as the live audio webcast of the conference call, following the results, can be accessed at:

https://www.ote.gr/web/guest/corporate/ir