Official UK domain name registry Nominet is warning of confusion caused by the sales tactics of a domain name reseller.

The reseller, UK Internet Registry Limited, has been sending documents resembling invoices to holders of .co.uk domain names, claiming that the .com version of the registrant's name is for sale.

But Nominet has no connection to the company and has posted a notice on its website stating as much.

"We would like to clarify that there is absolutely no association between Nominet UK - the official registry for .uk domain names - and the above company [UK Internet Registry]," the statement said.

"We would like to point out that Nominet UK does not proactively sell .uk domain names and we have no involvement with the registration of .com domain names," it added.

Companies should never be bounced into registering a domain name by the selling tactics of an unknown third party, Nominet cautioned.

Customers that have received a letter from UK Internet Registry are advised to contact Nominet.

When vnunet.com tried to contact UK Internet Registry it got only a recorded message asking callers to use email, as it was receiving "large and unexpected call volumes".