Unique web domain total tops 180 million

Researchers estimate that there are now roughly 183 million domains registered across each of the top-level domains (TLDs).

New domain registrations rose at a level of 12 per cent last year.

The study said that the .com TLD continues to be the most popular web suffix, comprising the majority of all web domains.

However, the use of 'country code' domains, such as .co.uk, rose by some 18 per cent.

The company estimates that country code TLDs account for 74.1 million domain names.

Of those country code domains, China's .cn was the most popular, followed by Germany's .de. The .net TLD was the fourth most popular TLD.

VeriSign said that the growth of new domains underscores the importance of maintaining the Domain Name System (DNS) which links the domain names with numerical IP addresses.

"DNS becomes even more critical to the overall infrastructure of the internet, not only as usage grows but as innovative products and services related to the DNS proliferate," said Jill Corso McNabb, vice president of naming services at VeriSign.

Researchers recently warned that the next challenge to the internet's structure may not come from the DNS, but from a lack of new IP addresses. Slow migration to the new IPv6 protocol could lead to a shortage of new IP addresses.