Delta Rocket Order Expected From Hughes : Aerospace: The deal would help McDonnell develop improved launch vehicles.

Hughes Aircraft Co. is expected to aid McDonnell Douglas Corp.’s development of a new version of McDonnell’s Delta launch rocket, sources familiar with the project confirmed Monday.

Los Angeles-based Hughes, the world’s largest builder of commercial satellites, plans to order at least 10 launches using the new Delta rocket and to take options on an additional 10 launches, giving the deal a potential value of $1 billion or more, the sources said.

The deal will help McDonnell--whose space group is based in Huntington Beach--to spend about $200 million for the new rocket’s development, the sources said.

McDonnell and Hughes, a unit of General Motors Corp., declined to comment. They are expected to formally announce the pact Wednesday.

The Delta rocket, which is known for its reliability, is an intermediate-size launch vehicle that McDonnell has built since 1960. The Delta’s major components are built in Huntington Beach (for final assembly in Colorado) and its first-stage main engines are built by Rockwell International Corp.’s Rocketdyne unit in Canoga Park.

The Hughes pact, among other things, would enable McDonnell to design a “Delta III” version of the rocket that would have more power than its predecessors, allowing the new rocket to lift heavier satellites such as those manufactured by Hughes, the sources said.

Such a plan would enable McDonnell to better compete in that market against such rivals as Lockheed Martin Corp. and Arianespace of France.