Citing differences in opinion about i-traffic's future direction, Owrid expressed displeasure at the recent consolidation that has occurred at Agency.com.
"I joined i-traffic, not Agency.com. When the two businesses were pulled together - which was necessary when the business got smaller - I came to the conclusion that it would be as valid to do what I want to do outside the company, he said.
Last week it was reported that Agency.com had merged its web design shop, Organic, back into the main business. Agency.com has taken a similar route with i-traffic, which used to be a separate profit-and-loss centre from Agency.com, but has now been folded back into the parent company.
Andy Hobsbawn, the managing partner of Agency.com London, said the recent consolidation was "trying to unify and unite the management processes, yet still offer the best combination of skills".
He denied Agency.com was suffering financially, stating "the office, like the European operation as a whole, is profitable".
Owrid, appointed to spearhead i-traffic's drive into continental Europe and work with clients such as British Airways and Cable & Wireless, joined the company in October last year.
He was formerly the managing partner at both Ogilvy & Mather and OgilvyOne.
Commenting on Owrid's departure, Hobsbawn said: "It was a mutual thing and very amicable. With his background we thought he would do better going back to something involving traditional media. He would make a bigger impact there."
Owrid plans to set up his own agency concentrating on integrated advertising solutions, but with a heavy emphasis on digital marketing.
"I've been thinking about where the interactive marketing communications business is headed, he said. "I'm talking to three to four key partners, and over the next two or three months we'll be putting together the plan for the new company."