The MediaEquals platforms will allow agencies to book print and digital ads across the Johnston Press regional titles, which include the Yorkshire Post and The Scotsman, through an online system.
MediaEquals trading platforms offer real-time reporting and campaign management, and integrate with media owners' back-office systems.
Northcliffe Media began using the online booking system earlier this year.
Neil Jones, group commercial and marketing director at Johnston Press, said: "MediaEquals will transform the booking process; reducing transaction costs for all of our customers and helping focus on delivering smarter media solutions, with less administration."
Gary Goodman, MediaEquals chief executive, said: "MediaEquals makes buying media a more streamlined process, and, as the UK’s largest regional publisher, Johnston Press is investing in efficiency."Follow @johnreynolds10