Oct 20 (Reuters) - Microsoft Corp used its monopoly position in computer operating systems to block the PC-sharing business of MiniFrame Ltd, according to a lawsuit filed by the small Israeli technology company.

The world's largest software company, which supplies the operating systems on 90 percent of the world's PCs, unfairly changed its licensing agreements and bullied MiniFrame's potential customers to prevent it from winning valuable contracts, the Israeli company said.

MiniFrame's SoftXpand software lets multiple users access the same PC operating system from multiple locations, using only a monitor, keyboard and mouse. The company said that does not violate Microsoft's original user agreements, which prohibit only multiple PCs accessing the same system.

The Israeli company claims pressure from Microsoft forced Hewlett Packard Co, JPMorgan Chase & Co and other large companies to drop plans to buy MiniFrame's products, costing it billions of dollars in sales.

In the lawsuit, filed in New York federal court late on Wednesday, MiniFrame is demanding more than $1 billion in damages.

Microsoft, which only this year concluded monitoring by the U.S. government following a settlement of antitrust charges in 2001, did not immediately respond to a request for a comment.

The case is MiniFrame Ltd v Microsoft Corporation, U.S. District Court for the Southern District of New York, No. 11-7419.

For the plaintiffs: Robert Morris and Timothy Helwick of Kramer Levin Naftalis & Frankel.

For Microsoft: Not yet available.

(Reporting by Bill Rigby)

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