A news agency plans to exploit the growing trend for celebrities posting photographs on the social networking website Twitter, by charging publications thousands of pounds to use them.

And Twitter photos captured by ordinary members of the public – depicting a breaking news story for example – could end up the same way, earning the agency cash but without any fee for the photographer who took them.

Entertainment picture agency WENN has confirmed that it has signed an agreement with Plixi, one of the firms that enables Twitter users to share their images, allowing WENN to charge a third party for publishing such pictures, according to an article by journalist?s trade publication Press Gazette.

WENN?s deal with Plixi gives the agency the right to charge the media for the commercial use of Twitter pics, as it would any other images it plans to sell.

Plixi’s terms of use for uploading photos to Twitter state that although the photographer retains copyright, they agree to hand over a ?worldwide, royalty-free and non-exclusive license? to use, distribute, reproduce, modify, adapt, publicly perform and publicly display such content whether on the service or through other media?.

WENN chief executive Lloyd Beiny told Amateur Photographer (AP) that Plixi first approached WENN to ?see if we could help them out?, after noticing that newspapers, magazines and websites increasingly publish images taken by celebrities from Twitter for free and without permission.

Singer Katy Perry last week became the latest celebrity subject to appear in a Twitter photo when her husband Russell Brand posted a picture he had taken of her without make-up – a story quickly picked up by the world’s media.

In an interview with AP, Beiny did not rule out selling on other types of Twitter images to the wider media, such as pictures of a breaking news story, if it were brought to its attention, whether featuring a celebrity or not.

?It [the agreement with Plixi] applies to all pictures but unless it is something really exceptional it is unlikely we would be interested in anything other than a celebrity,? he told us.

Beiny, who refused to divulge the financial details of its deal with Plixi, revealed that WENN would be also interested in striking agreements with other companies which allow Twitter users to share their images.

Firms providing such a service include Twitpic.

Beiny believes celebrities will not object to the wider publication of their images because by posting them on Twitter they have already ?shared them with the world?.