British companies are facing a scramble to protect themselves from "online porn squatters" after being warned that they have less than a week to prevent their brand names from being used as addresses for pornographic websites.

A new .XXX online domain created specifically for adult entertainment – a rival to the more common ".com" or ".co.uk" – is set to go live next year in an effort to encourage a more responsible approach to online pornography.

While official figures have yet to be released, a source intimated last week that some 15,000 companies worldwide have barred their names from appearing online with the new suffix.

While that figure is more than double what authorities expected to hear from at this stage, some of the world's biggest brands will be at risk from cyber-squatters should they miss the 28 October deadline.

ICM Registry, which is managing the registration of names to be protected, said it has reserved certain names free of charge at the request of child pro- tection agencies and "various governments, international organisations...as well as designated premium generic names".

In August, it was also reported that ICM had barred the names of various celebrities from being used.