America’s top three newspaper publishing companies are looking to team up to offer advertisers a one-stop clearinghouse for buying online adverts.

Gannett, McClatchy and Tribune want to form a single gateway, codenamed “Open Network”, with the intention of challenging the big three portals – Yahoo!, Google and Microsoft – which command the greater share of advertisers’ spend.

Newspapers have been haemmorhaging advertisers, which have been increasingly taking their business to the internet. Though many papers have websites, individually they have struggled to attract big-name advertisers.

Wall Street Journal reports the so-called “GMT” trio would each devote 10% of their online ad inventory to the joint effort. They hope to tempt car and phone makers.

They will also go up against a joint venture between Yahoo! and the so-called “Seven Amigos” group of newspapers, led by Hearst and MediaNews, which will allow the titles to sell online recruitment ads in return for deploying Yahoo! search across their sites.