Nortel Monday announced that CEO Bill Owens will leave the company in mid-November to be replaced by Motorola President and COO Mark Zafirovski.

Owens’ departure comes as a surprise given that the 65-year-old ex-vice chairman of the Joint Chiefs of Staff gave every indication he intended to remain CEO after leading Nortel through its financial scandal and refocusing the company on its enterprise operations. Owens became CEO after Nortel fired then-CEO Frank Dunn in April 2004 for cause after determining he helped orchestrate Nortel’s bogus accounting that forced the company to restate years of earnings.

Indeed, speculation has it that Owens’ determination to remain CEO prompted the abrupt resignation of COO Gary Daichendt in June after only three months at the company. Daichendt, an ex-Cisco sales executive, and CTO Gary Kunis, another ex-Cisco executive, were brought on to help inject some Cisco enterprise expertise into the telecom-stodgy Nortel.

Nortel just completed another reorganization that places even more emphasis on the enterprise.

Speculation now has it that Owens’ steadfastness may have cost him his own job.

"It makes you wonder what really went down with ex-COO Gary Daichendt, who apparently quit in May because he wanted to be CEO but Owens and/or the board showed no sign it was going to happen any time soon," wrote Canada’s National Post technology reporter Mark Evans in his blog. "In a nutshell, Owens’ departure -- was he fired, pushed or did he resign? -- is another one step forward, two steps back move for Nortel, which has now had three CEOs in the past 18 months."

In a statement, Nortel Chairman Harry Pearce thanked Owens for his contributions. Pearce himself is new Nortel blood, having been named chairman shortly after Daichendt and Kunis departed.

"At a moment of great challenge and enormous need in the history of this company, the Board turned to one of its own, whose long career embodied the highest levels of trust, integrity and distinguished leadership," Pearce said. "We needed an experienced, steady hand and Bill delivered. On behalf of our Board, our employees, investors, partners and customers, we will be forever grateful."

"Bill re-established stability within Nortel and credibility with all its stakeholders. He guided the company in becoming current in its financial reporting and maintained the loyalty of our customers. Mike can now build for the future on the strong foundation Bill Owens has given us," Pearce said.

Owens, in a statement, said: "As Nortel has said