Time Inc’s former executive vice president Evelyn Webster will step in as interim chief executive, working closely with US Editor Lee Glendinning to lead the commercial and operations team, while parent company Guardian News & Media searches for a permanent replacement.
She will report directly to David Pemsel, chief executive of Guardian Media Group, based in the UK.
Webster, formerly chief executive of Time Inc UK, left the media group in August after five years in the role during a reorganisation of the business’ sales and editorial divisions. She called the opportunity to grow the Guardian's US footprint "simply too good to pass up".
On his departure, Store said: "Now feels like the right time to hand over the reigns as I explore the next chapter of my career in an area I am passionate about, working to help senior corporate leaders drive stronger corporate citizenship by developing deeper, more enduring cause related partnerships with those dedicated to doing good in this world.
"I will leave the Guardian with enormous thanks and gratitude for the role I have enjoyed so much and the team that have supported me."
David Pemsel, chief executive officer, Guardian Media Group, added: “Eamonn has led the US business with passion and dedication at a time of huge volatility across the industry, and I’d like to thank him for all his hard work and many achievements.
"I am also delighted to have attracted someone of Evelyn’s calibre and experience, on an interim basis, to work closely with Lee Glendinning, the editor of Guardian US, and the senior team on the ongoing transformation of our US operations and our continued focus on maximising the enormous opportunities for Guardian journalism in the US market.”