NEW YORK ( TheStreet) -- Carl Icahn said on Monday he will not to continue to try and defeat Dell's ( DELL) near-$25 billion takeover by company founder Michael Dell and private equity firm Silver Lake Partners, after a string of legal rulings and decisions by Dell's special committee tasked with selling the struggling PC-maker turned against the billionaire activist's competing proposals. Icahn's decision likely cements Michael Dell and Silver Lake's takeover of the PC-maker, in what stands to be the biggest leveraged buyout since the financial crisis. In a letter to Dell shareholders, Icahn said the decision by Dell's special committee to ( change the voting standard of the takeover and the record date of the leveraged buyout to September 12 proved an "impossible" hurdle for his contesting efforts to take control of the company and pay out its billions in cash to existing shareholders. Silver Lake and Michael Dell asked that Dell's special committee agree to revise its merger agreement so absentee voters on a buyout transaction wouldn't be counted against the takeover consortium. In August, Dell's special committee accepted a 10-cent bid increase from the initial $13.65 a share offered by Michael Dell and Silver Lake Partners, along with a 13-cent special dividend as reason to change the voting standard of the transaction. Dell's special committe said at the time that Michael Dell and Silver Lake's increased bid increased the payout to shareholders by $470 million and gave them an extra quarter's worth of dividend payments. A Delaware count decided to uphold the change in the voting standard, another hurdle Icahn referenced in his Monday letter to shareholders. Icahn will still seek a higher price for Dell; however, he will do so by way of a court appraisal. Icahn also said that his involvement in Dell's LBO helped get shareholders a better deal. "We have therefore come to the conclusion that we will not pursue additional efforts to defeat the Michael Dell/Silver Lake proposal, although we still oppose it and will move to seek appraisal rights," Icahn said on Monday. Icahn last offer to shareholders was a $14 a share self-tender for about 72% of Dell's shares and a warrant, which Icahn said was worth up to $4 a share to investors. His proposal had the support of Southeastern Asset Management, Yacktman Asset Management and a number of large institutional investment funds. "I realize that some stockholders will be disappointed that we do not fight on. However, over the last decade, mainly through "activism" we have enhanced stockholder value in many companies by billions of dollars. We did not accomplish this by waging battles that we thought we would lose. Michael Dell/Silver Lake waged a hard fought battle and according to Chancellor Strine, the actions by Dell were within the Delaware law. We therefore congratulate Michael Dell and I intend to call him to wish him good luck (he may need it)," the legendary activist added.