The Guardian’s parent company has joined forces with rivals News UK and the Telegraph to create an online advertising business.

The Ozone Project has been launched in response to demand from advertisers for a one-stop shop to buy digital adverts across multiple leading news sites. When it launches in the autumn it will be possible for advertisers to buy online ad space on the Guardian, the Times, the Sun, and the Telegraph from a single site.

The deal involves only online adverts and all the newspaper groups will continue to have their own independent sales teams, who will compete against against each other for business. There is no crossover in editorial content or journalism, and no data will be shared between the newspaper groups.

The Ozone Project will be a standalone business with its own staff jointly employed by the three newspaper groups. The publishers said the project was in response to concerns about “brand safety, data governance, lack of transparency in the supply chain and ad fraud” following a number of online advertising scandals.

The announcement, made during the ad industry’s annual Cannes Lions International Festival of Creativity, follows years of discussions among UK newspapers about combining advertising sales teams, as money continues to divert to Google and Facebook, creating a tough financial outlook for traditional outlets. Guardian News & Media is on track to break even next year after a three-year plan to reduce financial losses from £57m.

“We are working together to build a better digital ecosystem for advertisers, readers and publishers,” Hamish Nicklin, GNM’s chief revenue officer. “The Ozone Project is a response to the challenges we all face and aims to facilitate the highest standard of digital advertising and ensure quality journalism and content continues to be funded.”