Skype, the Financial Times says that the internet calling service suffered a global outage on Wednesday. Skype said some users were having problems signing in. Users in the US, Asia and Europe complained of the outage on social network site Twitter. In its Twitter feed, the company apologised for the disruption and said it was investigating the cause. Around 3.30pm EST, it said the service was returning to normal, but that it may take several hours for everyone to be able to use it again. No explanation has been given so far for the outage.