The studio stated on its official website that lead network engineer David Aldridge's recent comments on the matter were a "joke".
"In rehearsal Aldridge was convinced that everybody got the joke," a Bungie representative wrote. "It was all in the delivery, he assured us, and he was certain it was clear that he was playfully riffing off of the recent rumours.
"Unfortunately, most people can't figure David out - they can't process him. And we don't expect them to. You can't process David Aldridge with a normal brain. You'd need tiger blood and Adonis DNA."
Speaking at a GDC session titled 'I Shot You First: Networking the Gameplay of Halo: Reach', Aldridge said that the firm was working on an action MMO with Activision.
It was previously rumoured that Bungie and Activision's first collaboration will be a shooter called Destiny.