United Technologies Corp's Pratt & Whitney unit has won U.S. Navy contract updates totaling about $1 billion to provide engines for the multi-national F-35 fighter jet program, the Pentagon said on Friday.

Included in this fourth low-rate initial production batch are 18 engines for conventional take-off and landing models and 19, for short takeoff/vertical landing F-35s, the Defense Department's daily contract digest said.

Pratt put the value of the deal at $1.1 billion, including production, spare parts, sustainment and delivery.

The deal provides a 15 percent savings on the conventional takeoff and landing/carrier models, compared with the third batch, Pratt said in a statement.

It demonstrates our commitment toward meeting aggressive cost reduction goals for the F135 engine, Bennett Croswell, president of Pratt's military engines business unit, added in the statement.

Deliveries of this batch are scheduled to start in the fourth quarter of this year, Pratt said. The engines will support aircraft for the United States, Britain and the Netherlands, it said.

Eight countries have joined the United States to co-develop the F-35 -- Britain, Italy, Netherlands, Turkey, Canada, Australia, Denmark and Norway.

(Reporting by Jim Wolf; Editing by Carol Bishopric)