A group led by Dell’s founder raised its offer for the struggling computer maker Wednesday in hopes of attracting more shareholder support for its plan to take the company private.

The 10-cent per share increase came just hours before Dell’s shareholders were scheduled to vote on the previous $13.65 per share offer from Michael Dell and investment firm Silver Lake Partners.

But the extra money comes with a catch, a stipulation that the offer’s fate be decided by the will of the shareholders who choose to vote in favor of the plan or against it, leaving out those who don’t vote at all. Previously, non-voting shareholders were counted as opponents of the proposal.

The Round Rock, Texas, company delayed its shareholder meeting for the second time in two weeks, moving it to Aug. 2 to give the special committee of its board time to consider the offer. The meeting had been set for Wednesday, after being delayed the week before in a sign that the offer didn’t have enough shareholder support.

‘Best and final proposal’

Michael Dell and Silver Lake said Wednesday that the new offer represents their “best and final proposal” and increases the total amount they are willing to pay shareholders by about $150 million, valuing the company at more than $24 billion.

Dell Inc.’s special committee is said to be seeking at least $14 a share from Michael Dell to cement the computer maker’s takeover, leaving them at an impasse after the founder said $13.75 was his best and final offer.

At $14, Dell’s special committee is open to a voting rule change proposed by Michael Dell and Silver Lake Management LLC that would give them enough shareholder support for a deal, according to a person familiar with the situation, who asked not to be identified because the matter is private.

Michael Dell and Silver Lake bumped the offer for the personal-computer maker by as the group seeks to end a six-month standoff with investors such as Carl Icahn. The sweetened offer is conditional upon the committee approving new voting terms that wouldn’t count abstentions as “no” votes. About 27 percent of shares — not including Michael Dell’s holdings — haven’t been voted, the buyers said today in a statement.

“There appears to be a lot of fence straddlers — it’s a real nail-biter right now,” said Ashok Kumar, an analyst at Maxim Group LLC. The provision to not count abstaining votes as ballots against the deal, “officially tilts this in favor of the management buyout team,” he said.

In their letter to Dell shareholders, Michael Dell and Silver Lake said they believe the change is “fair and reasonable” to the company’s other shareholders, especially given the new offer’s additional 10 cents per share for the stakeholders.

Icahn attacks Dell offer on Twitter

Icahn and investment firm Southeastern Asset Management have depicted the proposal as an attempt by Michael Dell to seize control of the company at a sharp discount to its long-term value. Icahn and Southeastern have offered a more complicated alternative, but they first need to block the deal with Michael Dell and then replace the company’s board in a follow-up battle.

Icahn used Twitter to send a message to followers Wednesday morning that said “all would be swell at Dell if Michael and the board bid farewell.”

In an open letter to shareholders released later in the day, the activist investor and Southeastern accused Michael Dell and Silver Lake of trying to “gut” the proposed deal of one of its few shareholder protections.

“To change the rules at the last minute is outrageous,” Icahn and Southeastern said in their letter.

The new offer from Michael Dell and Silver Lake is 26 percent more than the computer maker’s closing share price of $10.88 on Jan. 11, the last trading day before news of a deal surfaced. A majority of investors, excluding Dell’s 15.6 percent stake in the computer maker, will have to approve for the deal to pass.

But by sweetening the offer by such a small amount, the buyout team risks offending shareholders, said Jim Kelleher, an analyst at Argus Research.

“A dime won’t even get you a phone call,” said Kelleher, who recommends selling Dell shares. “There is a risk that the institutional investors, who were on the fence at $13.65, will not be neutral, but insulted by $13.75 and will swing to team Icahn.”

Michael Dell believes he can turn around the company by spending heavily to build better tablets while also diversifying into more profitable areas of technology, such as business software, data storage and consulting. But making those changes are likely to be tumultuous and temporarily lower Dell’s earnings, an upheaval that Michael Dell contends will be more tolerable if the company no longer has to answer to other shareholders.

Dell’s board says it want to sell to Michael Dell because it believes waiting for an uncertain turnaround is too risky. If the current deal unravels, analysts believe Dell’s stock could plunge below $9, reverting back to its levels of late last year.

(The Associated Press and Bloomberg News contributed to this report)