NeuLevel, the registry operator for the .biz top-level domain, will assign domain names to selected businesses and individuals after the offer closes at midnight on 17 September.
The .biz and .info top-level names are the first of the seven new domains that have been approved by ICANN and are designed to take the burden off oversubscribed existing domains.
John Fell, a partner at Masons, the IT specialist lawyers, said the new domain names might spark new "cybersquatting" rows.
"If you register a name with the simple intention of selling it to the rightful owner, the rightful owner could take you to court and get the name back," he said. "However, if you register the name for lawful purposes and there was a dispute, it would be hard to get the name back."
He added: "Businesses need to take a commercial decision as to whether they need to register with every [suffix] available. Registering a domain name prevents other businesses [and unscrupulous individuals] from using that name."
Some UK retailers, including HMV and WH Smith, have decided against registering for the new domains, saying there is no benefit in having a plethora of domain names.
But Barbara Cookson, IT partner at law firm Nabarro Nathanson, believes businesses should register for the new domains whether they want to use them or not, to protect themselves against abusive sites.
"Possession is nine-tenths of the law; it is much easier to have it in the first place," Cookson said. "If a business is going to get upset that another is using a domain name that it considers it rightfully owns, then it makes sense for that business to put in its own application because you don't know what a company will do with a domain name."