Icann, a United States quango which oversees the system that connects users to websites, said it would delay the cut-off from tonight to 20 April because of the glitch.
“ICANN constantly monitors the performance of the application system,” it said.
“Recently, we received a report of unusual behavior with the operation of the system. We then identified a technical issue with the system software.”
“Icann is taking the most conservative approach possible to protect all applicants and allow adequate time to resolve the issue”.
A spokesman told the industry website Domain Incite the problem was "not an attack".
The application process is designed to allow major brands are expected to create their own areas of the web, with theoretical examples such as .ford and .pepsi often cited.
So far firms including Canon and Google have confirmed they are bidding to create their own domain name suffixes. Most applications have been shrouded in secrecy, however, as bidders aim to avoid rivals.
An application costs around £120,000 and maintaining a domain name suffix at least £25,000 annually, so only large organisations are expected to apply.
Generic extensions such as “.web” are also up for grabs and expected to attract several applications, which could trigger an auction.
The changes have been several years in the making, and have proved controversial, with some claiming it will make the web more complicated and lead to more “cyber squatting”, whereby web addresses related to brands are speculatively acquired to parasitise traffic, or in the hope the brand owner will pay to regain control.
On the other hand, the new system could improve the security of online banking, for example. If a bank only provides its services via its own suffix then users are less likely to be duped by fake websites, it’s argued.
"We certainly expect to see applications from companies in industries plagued by counterfeiting and cybersquatting, as new [suffixes] offer important enhancements to security,” said Roland LaPlante of Afilias, a firm aiming to run suffixes on behalf of organisations.
Nominet, the not-for-profit organisation that runs the database of more than 10 million “.uk” web addresses, has applied to create new “.wales” and “.cymru” suffixes.
It is expected that it will take at least 18 months for the first of the new web address suffixes to work.
