Dell Inc. urged shareholders on Friday to vote for the $24.4 billion buyout offer led by founder and Chief Executive Michael Dell at a special meeting on July 18, saying the bid was superior to other strategic options.

Activist investor Carl Icahn and Southeastern Asset Management launched a $21 billion counter offer for Dell earlier this month that would allow shareholders to keep their shares.

Dell's board said in a letter to shareholders that it had looked into the possibility of continuing with or modifying the PC maker's business plan, changing its dividend policy, selling to a strategic buyer, and selling or spinning off parts of the business. It did not mention the Icahn offer.

"A sale to the Michael Dell/Silver Lake group ... is the best alternative available, in a challenging business environment it offers certainty and a very material premium over pre-announcement trading prices," Dell said.

Icahn has warned that if his leveraged recapitalization proposal was rejected, he would rally shareholders to vote down Michael Dell's offer.

Icahn made several requests for information from Dell, including a request for data room access for a potential lender.

But the company declined, saying it would not provide more information unless the board determined that Icahn's proposal was superior.