LONDON—Grayling CEO Pete Pedersen has resigned after two years in the role.

Pedersen, who departs immediately, joined Grayling from Edelman in early 2013. Paul Taaffe, who arrives as parent company Huntsworth's new CEO in April, has been charged with hiring Pedersen's successor.

Current Huntsworth CEO Lord Peter Chadlington said that Pedersen had "made an important contribution to Grayling and its repositioning as a digitally focused international PR company building multi-national client engagements."

Under Pedersen's leadership, Grayling has restructured its US operations, but — like his predecessor Michael Murphy — has found sustained global growth elusive.

"I'm the kind of guy who always wants to move faster and do more and do everything all at once," Pedersen told the Holmes Report, denying that he had grown frustrated. "We've done as much as we possibly can do in the time frame that we've had."

"I'm awfully proud of what the management team and I have accomplished over the past couple of years," he added. "We set a pretty bold course for Grayling and recruited a bunch of great talent. We set about creating a US operation from scratch and along the way we earned the trust of quite a few new clients."

Pedersen, who is based in Seattle, noted that he wishes to spend more time "closer to home".

"This business is going to look a lot different in five years than it does now and I'd like to be at the cutting edge of that," he also said. "With the arrival of a new management team at Huntsworth and the start of a new fiscal year, it seemed an opportune time."

Prior to joining Grayling, Pedersen spent 20 years with Edelman. His departure follows a series of changes at Huntsworth, including Taaffe's hire and the arrival of new chairman Derek Mapp.

Huntsworth has endured challenging trading conditions since the onset of the global recession, thanks in large part to its over-exposure to European markets. Last year, the group issued a profit warning, amid continued malaise from its PR firms. Grayling, the largest of its assets, declined by 6.4% in 2013, with 2014 results imminent.