NEW YORK, Oct 11 (Reuters) - Cameron and Tyler Winklevoss -- the famous twins who claim to have come up with the original idea for Facebook -- have lost a bid to appeal a decision last year that awarded the law firm Quinn Emanuel Urquhart & Sullivan a $13 million contingency fee stemming from the twins' settlement with the social-media giant.

On Oct. 6, New York's Appellate Division, First Department, dismissed the case brought by the Winklevosses. The twins had fought against paying the legal fees by arguing that the law firm committed malpractice in reaching a $65 million settlement in an intellectual-property dispute between Facebook and ConnectU, the Winklevosses' social-network website. The dispute was the subject of the film "The Social Network."

The brothers alleged that in reaching the settlement, the law firm miscalculated the value of Facebook stock. They also asserted the law firm revealed the amount of settlement in a newsletter, despite a confidentiality agreement.

An arbitration panel in August 2010 determined that the Winklevosses should pay the fees. In November 2010, New York Supreme Court Richard Lowe III confirmed the arbitration decision. Their appeal to the First Department followed.

In a one-page decision, the five-judge appeals panel granted Quinn Emanuel's motion to dismiss with "due deliberation having been had thereon."

Attorneys at Quinn Emanuel declined to comment.

Sean O'Shea, the attorney for the Winklevosses, did not immediately return a phone call. He is with O'Shea & Partners in New York.

The case is ConnectU v. Quinn Emanuel, No. 602082.

(Reporting by Leigh Jones)

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