Dell's plan for a private equity buyout ran into a potential snag Thursday as corporate raider Carl Icahn revealed that he has a stake in the computer giant and is opposing the deal.

Icahn, in a letter made public by the company's board of directors, said the plan to take the company private in a $24.4 billion buyout led by founder Michael Dell "is not in the best interests of Dell shareholders and substantially undervalues the company."

The investor known for moves on companies ranging from MGM to Yahoo! said that Dell, instead of going private, should make a special dividend payment to shareholders by using cash, assets or by borrowing.

This plan would give Dell shareholders 67 percent more than the offer of $13.65 per share.

"We see no reason that the future value of Dell should not accrue to ALL the existing Dell shareholders -- not just Michael Dell," Icahn said in the letter.

Icahn said his investment firm had taken a "substantial" stake in Dell, without elaborating. CNBC television reported the stake to be around six percent.

If Dell allows the buyout to move ahead, "we anticipate years of litigation will follow challenging the transaction and the actions of those directors that participated in it," Icahn said.

He said there will be questions about potential conflict of interest because of Michael Dell's ties to board members.

Dell's special board committee evaluating the options said it was "currently conducting a robust 'go-shop' process to determine if there are third parties interested in proposing alternative transactions," and would "welcome Carl Icahn and all other interested parties to participate in that process."

On Wednesday, the board defended the buyout plan as in the best interest of shareholders, but said it may continue looking at other offers past a March 22 deadline.

At least two major institutional shareholders have said they would vote against the plan.

The buyout plan is backed by equity investment firm Silver Lake and would include a $2 billion loan from Microsoft.

The move would delist the company from stock markets and could ease some pressure on Dell, which is cash-rich but has seen profits slump as it tries to reduce dependence on the shrinking market for personal computers.

Dell shares dipped 10 cents to end Thursday ay $14.22 as analyst comments on the situation were mixed.

Brian White at Topeka Capital Markets raised his target price to $18 a share, saying "too many forces are pushing toward a higher buyout price."

Jefferies analyst Peter Misek said he sees an agreement for the buyout at $15 a share.

"Our conversations with investors lead us to believe that most want a raised bid, but that they are also cognizant of the lack of competing bidders and of the secular headwinds facing Dell's PC business," Misek said in a note to clients.

"We also think Icahn could be satisfied with a raised bid."