The Consumers' Association of Ireland (CAI) has warned companies, sole traders, State organisations and community groups about a guide inviting them to join its listings.

While the form seems only to ask the addressee to confirm that the details for inclusion in the guide are correct, the small print points out that a charge of €717 (£564) per annum for three years is being accepted.

The guide, the European City Guide, is to be issued in both hard copy and on the Internet.

Mr Herbie Ellis, of 24Seven, a Dublin advertising and marketing company - the first business listed on the Internet guide for Dublin - said he filled in the form and returned it to the Barcelona-based company without reading the small print.

"I got billed for it and I ignored it. They wrote to me a few times, demanding payment, threatening letters, but I just kept on ignoring them."

He does not intend paying, he said.

The Internet site lists hundreds of Irish companies, sole traders, restaurants, and community groups, which it would seem filled in the form.

It lists addresses and phone numbers from 29 European jurisdictions. A representative of the company could not be contacted.

A spokesman for the CAI said the forms are another indication of how carefully people should read documents before they put their names to them.

"The advice is always to read something carefully and make sure it does not involve a payment before you affix your signature."

He said it is another instance of a large, sophisticated and multi-jurisdictional operation which includes the Republic in its target area, a phenomenon, he said, that is likely to become increasingly common.