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Iger has held the title of both chairman and CEO since last year, and is scheduled to step down as CEO and simply hold the chairman role starting in 2015.
ISS, Glass Lewis, along with Calstrs and PGGM also oppose Disney's compensation plan and are encouraging shareholders vote against the current proposal, which links Iger's compensation to the stock performance. In Disney's fiscal 2012, Iger brought home a total of $40 million in compensation, while the stock rose 76 percent. They're also backing another proposal that allows shareholders who own more than 3 percent of Disney shares continuously for three years to nominate directors.
CalSTERS CEO Jack Ehnes told CNBC that he's committed to maintaining the pension fund's $260 million investment in Disney, regardless of the outcome of the shareholder vote, but he is pushing for change to secure a better corporate structure.
"It is the job of the CEO to manage the company and it's the job of the chairman of the board to protect the interests of the shareholders," Ehnes said, explaining why he wants the positions split.
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Glass Lewis' David Eaton acknowledges that Disney has had a great year, but said that his organization is encouraging investors to correct "risks and issues that could affect shareholder value in the future." Disney board members will have a "slightly contentious meeting," Eaton predicted. "I think the pay issues are definitely going to be discussed."
Disney won't comment and simply points to its record. And Iger's record is indisputably strong. Since he became CEO on September 30, 2005, Disney's shares have gained 138 percent, while the S&P 500 gained just 25 percent over the same period.
In its most recent earnings, the fiscal first quarter of 2013, the company reported 79 cents per share, beating expectations by three cents, while revenue of $11.34 billion also came in higher than expected. And in its fiscal 2012 Disney reported record revenue and profit.
(Read More: Disney Earnings Beat; 'Star Wars' Spinoffs Planned)
—By CNBC's Julia Boorstin; Follow her on Twitter: