From 9 March, Loughran will become chief marketing officer at Linkdex. The company has offered SEO services for agencies and in-house marketing teams for the last five years.
He said: "I’ve seen at first hand the growing importance of the organic search channel to our clients at Dentsu Aegis Network.
"To help deliver against business growth metrics in an increasingly globalised and convergent world, clients require best of breed technology and smart people. Linkdex has both and is on a compelling growth trajectory."
Loughran joined Dentsu Aegis Network, the group behind Carat, Vizeum, Isobar, iProspect and Mcgarrybowen, in August 2011. Prior to the DAN he worked at MEC, as the business development director, and HMV.
Mark Smith, the chief executive of Linkdex, said: "Linkdex continues to double in size year on year.
"We’re now at the stage where the business is able to attract and utilise real talent in all areas of the business.
"Having a world-class CMO who understands the needs of client and agency partners is a key part of delivering the next leap in global growth."