Microsoft cannot secure the Skype trademark in 28 Member States of the European Union. Application for registration of a well-known brand was rejected by one of the courts of Europe. The reason for refusal is similarity to previously registered trademark of Sky television.
The company's logo is made up of the same Skype word designation and arched lines representing contours of the clouds. So that there is meaningful allocation of the word designation “sky” as the clouds are in the sky.
It is worth noting that Skype trademark registration refusal does not prevent its further use, but in the absence of claims on the part of a similar trademark Sky.