Starwood Hotels & Resorts Worldwide Inc sued Hilton Hotels and two senior executives in federal court on Thursday, claiming confidential information was stolen during Hilton's pursuit of a new lifestyle chain.

The Hilton executives named in the lawsuit filed in the U.S. Southern District of New York are: Ross Klein, head of luxury & lifestyle brands, and Amar Lalvani, head of development for the segment.

Hilton, a unit of Blackstone Group LP, hired both men, who had been Starwood executives closely involved in the company's W Hotels brand, last year after the hotelier was taken private in a leveraged buyout by Blackstone.

Hilton Hotels Corporation is aware that a lawsuit has been filed, but we have not yet seen a copy. We will respond appropriately in due course, Hilton spokeswoman Ellen Gonda said in an e-mail.

The complaint said the two executives aided and abetted by Hilton, ...stole massive amounts of proprietary and highly confidential Starwood information which was used to expedite Hilton's entry into the lifestyle hotel market, reposition its luxury brands and substantially reduce its costs and risks of doing so.

Hilton announced last month the launch of a new lifestyle brand called Denizen led by Ross, with developments planned in cities ranging from Beverly Hills to Abu Dhabi.

The lawsuit seeks monetary damages and a court order that would stop the Denizen projects.

The wholesale looting of proprietary Starwood information, including a step-by-step playbook for creating a lifestyle luxury hotel brand, unfairly enabled Hilton to launch a new brand in only nine months instead of the usual three to five years, Kenneth Siegel, Starwood's general counsel said in a statement.

The case number is: U.S. 09 CIV 3862.

(Reporting by Deena Beasley, editing by Leslie Gevirtz)