City AM's Martin Ashplant is to return to Metro as digital director.
In the newly created role Ashplant will be responsible for "delivering the newspaper's digital content strategy".
He worked at Metro for six and a half years before joining City AM in May 2014.
Ashplant was head of digital content for Metro for four years from 2010 when its website attracted less than an average 200,000 unique users a day.
In the month he left for City AM, this figure was more than 1.2m. This was two months after Metro's website operation was integrated with DMGT sister site Mail Online.
Metro's unique daily user average peaked at 1.6m in July this year, but has since fallen to less than 1.2m.
According to Metro, Ashplant has overseen a trebling of monthly online audience on City AM where he has led the digital commercial strategy. This included recently preventing people using ad blockers accessing the website.
Ashplant will join Metro in January and his responsibilities will include "overseeing the tablet and phone editions and increasing the reach of Metro content via digital distribution platforms".
Ashplant said: "I am looking forward to returning to Metro in 2016 after a hugely rewarding time at City AM, where I’ll be leaving behind an exceptionally talented team. There’s a fantastic opportunity at Metro to build on the success of the award-winning tablet edition and do something special in the mobile app space and I’m excited to get started.”