Harrison will be overseeing Infogrames' studios and development, and along with Gardner will be spearheading an initiative that aims to make US subsidiary Atari a leader in online gaming.
The online component of his new position fits in well with Harrison's philosophy on digitally-delivered content. He has long been a proponent of digital distribution and community play.
Atari and Infogrames have seen tough times over the last couple of years, with hurdles that included the departure of key management, restructuring initiatives that saw significant layoffs, studio sell-offs and financial losses.
However, recent Infogrames financial reports have shown lessened losses. A team led by management powerhouses like Gardner and Harrison could be just what Infogrames and its Atari brand need right now to build momentum.
Harrison said in a statement, "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."
Gardner stated, "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!"