British satellite broadcaster BSkyB has confirmed it was locked in a five-year dispute with Skype about the internet phone company's use of the "Sky" part of its name.
The dispute was revealed in a 250-page document, which announced the internet phone company's plan to raise $100 million on an initial public offering on the Nasdaq stock exchange.
The statement released for the initial public offering (IPO) revealed that Skype is contesting a number of challenges from BSkyB over the use of the word "Sky" in its brand name and logo.
BSkyB confirmed that it had asked trademark authorities to look into the matter.
A BSkyB spokesman said: "In a world where entertainment and communications services are increasingly converging, it is clear that companies that operate in the same or similar sectors need to ensure that they can protect their brands.
"Our research demonstrates that similarities in name and logo have the potential to confuse a great many consumers.
"This is of particular concern in respect to Skype wishing to extend its trademark applications to cover TV-related products and services."
Skype said in its IPO registration statement that BSkyB was opposing it in the European Union, India, Brazil and Norway.
The EU's trademark registration office has already ruled in favor of BSkyB over Skype's logo, but Skype said it intends to appeal that decision.