Plans to establish a new internet domain specifically for pornography are to proceed after internet regulators approved the .xxx suffix for adult entertainment sites, three years on from a decision to block the move.

Proposals to create a new adults-only domain date back as far as 2003 when moves to open up the number of major domain names were announced by the Internet Corporation for Assigned Names and Numbers (Icann), which administers millions of internet addresses.

However, Icann blocked the plan in 2007 after long deliberations and threats in the US from the Bush government, which opposed the creation of .xxx on moral grounds and said it would override Icann if necessary.

On Friday, the board of Icann said that it would allow the .xxx domain to be overseen by ICM Registry – the backer of the scheme – although a number of board members reportedly opposed the resolution.

The backers of the scheme said that it will provide reassurance to those visiting pornography websites that they are protected from the risk of viruses, identity theft, credit card fraud and inadvertent exposure to child abuse images.

They also claim that it will provide individuals and parents who wish to avoid adult entertainment sites the opportunity to filter out unwanted .xxx material.

Anti-pornography campaigners argued that the move legitimises the sex industry, and it also drew criticism from some parts of the adult entertainment business, who said that forcing sex sites into a specific corner of the internet would inevitably increase censorship.

PCmag.com reported that one Icann board member who opposed the resolution said that .xxx would encourage filtering and, ultimately, censorship.

"I believe that the creation of .xxx would mark the first instance of an action by this board that may directly encourage such filtering," said George Sadowsky, a US computer scientist.

"In my judgment, the board should not be taking actions that encourage filtering or blocking of a domain at the top level. Further, I believe that the filtering of so-called offensive material can provide a convenient excuse for political regimes interested in an intent on limiting civic rights and freedom of speech."

Stuart Lawley, CEO of ICM Registry, described the decision as a "landmark moment" for the internet and said that the first .xxx websites would be going live by June or July of this year.

"For the first time there will be a clearly defined web address for adult entertainment, out of the reach of minors and as free as possible from fraud or malicious computer viruses," he added.

Lawley said that ICM Registry will be talking with governments around the world "to ensure they fully understand the nature and self regulatory nature of .xxx".

According to a statement released by ICM Registry, the new domain name will be regulated by IFFOR, which was described as an independent non-profit entity made up of a seven-person policy council, including a child protection representative, a privacy and security expert and representatives from the pornography industry.