Blueboomerang.com houses directory services from Haymarket's range of titles and directories division. It claims to be "the most comprehensive 'who does what and what's their phone number?' service in the marcomms sector".
The company said the site will be expanded in phases, beginning with marketing communications services.
Paul Mann, ad director of the directories division, said: "Quite simply, we are recognising the importance customers are putting on web delivery."