As many as one in six firms has to register its second or third choice of web address because of URL disputes, according to new research.

However, the World Intellectual Property Organisation (Wipo), an arm of the UN, last week said that it would continue to protect the rights of trademark holders and fight cybersquatters - speculators who register web addresses associated with brands and trademarks in the hope of selling them on at a profit.

A survey carried out by internet keyword company CommonName found that 17 percent of a sample of 115 companies had been forced to choose their second or third choice of domain name because their preferred options were already assigned to other companies. "Domain names are being registered by the millions, making it more and more difficult for new businesses to register relevant URLs," said CommonName chief executive Yurong Lin in a statement.

Antony Gold, intellectual property partner at law firm Eversheds, said his firm dealt with domain name difficulties on a daily basis. "People are always rebranding and are continually running into problems. This is a vibrant area for abuse," he added.

Gold said that the challenge for firms was to deal with the problem in a cost-effective way, and he advised them to either run active sites relating to their brands or to hold "defensive registrations" - sites registered but not necessarily used, in order to prevent others from taking them. "If you have brand names and trademarks you have to make sure that no one else can get them."

Firms wanting to protect their interests will benefit from Wipo's continued efforts to stamp out cybersquatting. Francis Gurry, deputy director general of Wipo, said, "We need to ensure that the rights of legitimate trademark owners are not diluted."