Harrison, whose departure from Sony was announced a week ago, will report to recently appointed CEO David Gardner, working with him to help turn Atari into 'a leading online game company'. He will oversee Atari's studios and content development and help attract new internal and external development talent.
Commented Harrison: "This is the perfect time to join Infogrames and help shape the future of Atari - one of the industry's legendary brands. As the game business moves rapidly online I believe we have an outstanding opportunity to create amazing network game and community experiences for players the world over. I am especially excited to be working on this challenge together with David, one of the most respected leaders and successful executives in our industry."
Publisher Atari is in the midst of a revamp - it recently signed up other top-tier industry exec and former EA worldwide studios head Gardner to see the struggling firm through what he called a 'reboot'.
Gardner stated when he joined Atari a month ago that he wanted to assemble a 'world-class management team' - a promise now made good on via the hiring of Harrison - and 'build an online platform for distribution and gaming' which would help restore Atari to profitability.
At Sony, Harrison most-recently led the platform-holder's still-in-the-works efforts behind shifting online play towards community and user-made content via upcoming virtual world Home and PS3 title Little Big Planet.
Gardner commented: "I am pleased to welcome Phil to Infogrames. He has an outstanding reputation in the industry, as one of the key leaders behind the success of PlayStation. We have been seeking an opportunity to work together for some time and I am certain he will be able to make a significant contribution to the publishing strategy of the Group.
"Drawing upon Infogrames' strong financial foundation, Phil will have the means to attract new talent, develop studio and online capabilities, and drive forward our publishing activities. I want to work with people that understand fun for consumers and fun in the company culture. We're going to have a lot more of both around here with Phil."