Skype was recovering on Thursday from a major outage that left millions of people unable to use the popular Internet communication service.
Skype chief executive Tony Bates said in a blog post and video that at 1700 GMT, some 16.5 million people were online on Skype around the world, about 80 percent of normal traffic.
Bates "apologized profusely" for the technical problems that began Wednesday and "took almost every user offline."
"This has been a very tough 24 hours for many of our users," he said. "Our priority has been to stabilize the problem, and then to begin to restore access to Skype."
Bates said engineers had "stabilized Skype's core functionality -- IM (instant messaging), audio and video -- but it will take longer for us to restore offline IM and group video calling."
He said the company was planning to offer Skype credit vouchers to paying customers inconvenienced by the outage.
In a blog post, Skype explained that the outage was caused by a lack of computers known as "supernodes" and that engineers had created new "mega-supernodes" in a bid to get the service up and running again.
Skype, which was founded in 2003, bypasses the standard telephone network by channeling voice, video and text conversations over the Internet.
The company announced plans in August to raise up to 100 million dollars in shares by listing on the Nasdaq stock exchange.
Technology blogger Om Malik, writing on his blog GigaOm.com, said the outage was a serious issue for a company that is "starting to ask larger corporations for their business."
"If I am a big business, I would be extremely cautious about adopting Skype for business, especially in the light of this current outage," Malik said.
"(Skype) needs to ensure that it doesn't go down. Even for a few minutes."
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