Activist investor Carl Icahn is suing Dell to prevent the PC maker from changing crucial details of a buyout offer from founder Michael Dell that Icahn stridently opposes.

Icahn's complaint seeks to prevent the company from setting a new record date for a special meeting at which shareholders will vote on an offer that Dell recently raised.

Dell and the Round Rock, Texas, company agreed months ago on a deal in which Michael Dell will buy the company for $24.4 billion, or $13.65 per share. Icahn and other big Dell investors have said that offer undervalues the company.

Dell has since raised that offer to $13.75 per share, and a board committee has proposed changing the record date for a special meeting on it. That would allow a bigger pool of stock owners to cast ballots on the raised offer.

Dell Inc. shareholders are scheduled to vote today on the $13.65-per-share offer. But the Wall Street Journal has reported that the buyout group led by Michael Dell is nearing a new agreement with the company's special committee to increase the deal's price in exchange for a change to the voting rules behind it that would help get the deal approved.

Icahn filed a complaint Thursday against the company and its board members in the Delaware Court of Chancery. Icahn argued that if the company is allowed to set a new record date for the meeting, it should hold it at the same as the annual meeting.

Icahn wants to use the annual meeting to replace Dell's board and then oust Michael Dell, the chairman and CEO.

The investor said in a statement that he also wants a declaration that Dell's board breached its fiduciary duties to shareholders by, among other things, adjourning a July 24 special meeting without also scheduling the company's annual meeting.