Goodby, Silverstein & Partners and Denny's have parted ways, the agency has confirmed.
"We created something we're really proud of," said Jeff Goodby, co-chairman and creative director of the Omnicom shop. "We hope they use the best parts moving forward."
Goodby declined to elaborate, but sources said the agency and Spartanburg, S.C.-based restaurant chain were having creative differences over the future direction of the advertising.
Denny's hired San Francisco-based Goodby in January 2009 and made its Super Bowl debut with commercials touting its Grand Slam free-breakfast promotion shortly thereafter.
The company served 2 million free Grand Slam meals two days after the 2009 Super Bowl and repeated the promo on this year's game
with the introduction of a new ad series that warned chickens to get out of town because "it's going to be a tough week for egg layers."
Denny's spent $58 million in measured media last year, according to Nielsen. From January to April of this year, it spent $33 million.
The company has had a series of management changes of late, with CEO Nelson Marchioli, who had led the firm since 2001, leaving in June amid pressure from investors to transition Denny's to a franchise-oriented business model.
Denny's representatives did not immediately respond to queries seeking more information.