I assume that you are talking about final dividend recommended by Directors & declare by shareholders.
Declaration of Final Dividend is an ordinary business as per Section 173. Final dividend is declared in AGM by shareholders and once final dividend is declared in AGM you can not amend or declare fresh dividend by holding EGM.
To conclude a public company can not declare dividend in an Extra Ordinary General Meeting. The answer above is based on my personal understanding of law. Views of other experts solicited.
05 June 2009
As per Deptt of Companies Affairs Circular No. 22 [7/9/74-CL-II], dated 25-09-1975 it is beyond the powers of the company to declare a further dividend after the declaration of dividend at the Annual General Meeting.