Updated from 8:02 a.m. EST to provide analyst comments regarding deal in the fifth and ninth paragraphs.

NEW YORK ( TheStreet) -- The drama between Michael Dell, Carl Icahn and the battle for Dell ( DELL) may be coming to an end, as an influential proxy advisory firm backed Dell's bid for his company.

In a surprising move, proxy advisory firm Institutional Shareholder Services (ISS) endorsed Dell's $13.65 per share offer for the Round Rock, Texas-based company as the best deal for shareholders. Dell, who is CEO of the company, joined up with private equity firm Silver Lake Partners on the bid.

"After evaluating the risk of accepting the offer -- truncation of value if the business transformation is successful -- versus the risk of rejecting the offer -- meaningful loss of value if the business transformation falters -- ISS recommends clients vote FOR this transaction, which offers a 25.5% premium to the unaffected share price, provides certainty of value, and transfers the risk of the deteriorating PC business and the company's on-going business transformation to the buyout group," the proxy advisory firm said in a statement.

Shareholders, who are scheduled to vote on July 18 on the $24.4 billion buyout, may have been thrown a loop. Many were expecting ISS to not back the go-private offer from Dell and Silver Lake, as Carl Icahn had a competing offer for the company, paying $14 per share.

Some were surprised that, given Icahn's higher bid, ISS chose to go with the Silver Lake/Dell deal. "The Dell Special Committee indicated that 'Given the Company's business challenges, intensifying competition and deteriorating industry trends, a sale at $13.65 per share in cash provides the highest value and greatest certainty of any available alternative'," wrote Topeka Capital Markets analyst Brian White in a research note. "We also believe rejection of this transaction would expose Dell and its shareholders to serious risks and uncertainties that will harm the Company's business and erode shareholder value."

In Icahn's offer, he would've purchased 72% of the company, and left a portion of it still publicly traded. The offer from Dell and Silver Lake takes the entire company private.

Many institutional investors, including Southeastern Asset Management, T. Rowe Price, Yacktman Asset Management and Pzena Investments are against the offer from Dell and Silver Lake. Combined, these shareholders own around 18% of the company, and may still provide a road block to getting a deal done.

Dell, who owns 16% of the company, may still not get the opportunity to take his company private, since he is not allowed to vote in the deal. Proxy firm Glass Lewis still has to make its decision on whether Dell's offer is best for shareholders, or whether they should consider alternatives. That decision is expected to come sometime within the next week.

Though ISS is an influential proxy firm, it may not be completely over for Icahn, says White. "If the Silver Lake transaction is voted down, Mr. Icahn would like to see a new group of directors elected at the 2013 Dell annual shareholder meeting and also implement the proposed $14.00 tender offer."

Excluding Dell's ownership stake in the company, approximately 43% of shareholders need to vote in favor of the deal for it to pass.

Dell shares were higher in Monday trading, up 2.84% to $13.40.

-- Written by Chris Ciaccia in New York

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