LOS ANGELES (AP) _ A multi-billion dollar contract to build the next generation of spy satellites has been awarded to Martin Marietta Corp., two newspapers reported today.

Marietta outbid rivals Lockheed Corp. and TRW Inc., and will make the satellites at its plant in Denver, the Los Angeles Times and The Washington Post said.

TRW had orginally won the contract late last year. But the General Accounting Ofice ordered new bids after Marietta and Lockheed claimed TRW submitted an unrealistically low bid.

The contract was issued by the National Reconnaissance Office, which is the development and procurement arm for satellites used by the Central Intelligence Agency and the Air Force.

All three firms declined to comment on the program, which is classified.

The Post said the contract was worth up to $2 billion, and the Times' sources said design and production would cost from $5 billion to $10 billion over eight to 10 years.

The satellite, known by the designations 7795 or P-81, would use an advanced radar system to keep track of other nations' planes, ships and ground equipment.