NEW YORK (Reuters) - Saudi Arabia, its defense minister and its ambassador to Britain won a ruling in a U.S. court on Tuesday dismissing them as defendants in massive litigation growing out of the September 11th attacks on America.

U.S. District Judge Richard Casey ruled in a lengthy written order that Saudi Arabia, Saudi Defense Minister Prince Sultan Prince Turki al-Faisal, the country's ambassador to Britain, all have immunity from the litigation.

The judge also dismissed a number of other parties as defendants including Arab Bank, Al Rajhi Bank, and Saudi American Bank.

The rulings stemmed from eight cases that were consolidated before the Manhattan federal judge, who is considering pre-trial matters. The complaints alleged that more than 200 defendants helped support and fund Osama bin Laden and his al Qaeda network.

The cases were filed on behalf of more than 3,000 plaintiffs including representatives and family members of those killed in the Sept. 11, 2001 attacks as well as survivors and insurance carriers.

The plaintiffs alleged that the Kingdom of Saudi Arabia, the Saudi Royal Family and people prominent in Saudi society made it possible for al Qaeda to grow into a "sophisticated global terrorist network."

The plaintiffs also charged that Saudi Arabia maintained and controlled charities within al Qaeda's structure.

Saudi Arabia responded to the suits saying that it has worked with the United States to share information in the fight against terrorism and that the State Department has not designated the Kingdom as a state sponsor of terrorism.

It also said that the 9/11 Commission in the United States had found no evidence that Saudi Arabia supported those who attacked the World Trade Center and the Pentagon.

In his ruling, the judge refused to immediately throw out allegations against National Commercial Bank, Saudi Arabia's largest, which the plaintiffs say bin Laden and al Qaeda used for their operations.

The bank, which is mainly state-owned, contends that it has immunity as agent of the government, but the judge said further information was needed to determine its status.