On June 27, 2005 Micromuse agreed to settle the securities class action lawsuit.

On December 30, 2003, Micromuse announced that filing of its annual report on Form 10-K would be delayed pending completion of an internal inquiry, primarily regarding accounting for accrued expenses and expense recognition, and that it expected the inquiry to lead to a restatement of financial results for the fiscal years ending September 20, 2000, 2001, 2002 and 2003. In reaction to this announcement, the price of Micromuse common stock dropped by 12.4%, from a closing price of $6.90 on December 29, 2003, and closed the day down 4% at $6.59 on volume ten times greater than average. company Prior to the announcement, insiders allegedly sold Micromuse stock for proceeds of approximately $174 million.

If you bought the securities of Micromuse between January 20, 2000, and December 29, 2003, and sustained damages, you may request appointment by the court as a lead plaintiff no later than March 15, 2004. A lead plaintiff is a representative party that acts on behalf of other class members in directing the litigation. In order to be appointed lead plaintiff, the court must determine that the class member's claim is typical of the claims of other class members, and that the class member will adequately represent the class. Under certain circumstances, one or more class members may together serve as lead plaintiff. Your ability to share in any recovery is not, however, affected by the decision whether or not to serve as a lead plaintiff. You may retain other counsel of your choice, to serve as your counsel in this action. Alternatively, you may choose not to take any action and remain a silent member of the class.