Sullivan and former co-partner Andrew Stone (who has since left) each owned a 20 per cent stake in the agency, reported New Zealand's National Business Review.
The Review also reported that the agency's eight staff members, including digital partner Jose Alomojan, have been kept on and will be supplemented by a team of contractors.
In a release, O'Sullivan said that as most of the work available in New Zealand was project-based, the new agency model would be based on that. "The Collective can be about working with one person or many," he said. "It all depends on the task. The Collective will partner with clients like Qantas, AA Travel, Phoenix and Telecom. We will work with agencies as well.”
The renamed agency will still work with Droga5 on the Qantas account and will be affiliated with Los Angeles-based agency World Wide Mind.
The management change means that Droga5 now has offices only in New York and Sydney. The agency launched the New Zealand office two years ago, but had suffered a series of setbacks earlier this year, chief of which was the loss of major client ASB Bank to Saatchi & Saatchi in April.