NASA will suspend contract awards to two companies charged with carrying cargo to the International Space Station following a complaint by a consortium set up by three leading contractors.

PlanetSpace, a partnership of Boeing, Lockheed Martin and Alliant Techsystems Inc., submitted the protest Wednesday to the United States government accountability office, saying it had a superior offer.

"[PlanetSpace] received a higher mission suitability score from NASA's source evaluation board and was lower in cost than one of the two proposals selected by NASA," PlanetSpace said in a statement. "Thus, the PlanetSpace proposal represented better value to the government."

The Chicago-based consortium had entered a bid for the contracts. But in December, NASA instead awarded the contracts to California-based startup Space Exploration Technologies Inc. and Orbital Sciences Corp., based in Virginia. The former, also known as SpaceX, has a contract for 12 flights at a price of $1.6 billion US, while Orbital will make up to eight flights for $1.9 billion.

The contracts call for a minimum of 20 tonnes in cargo mass to be delivered to the space station.

The GAO, which is expected to issue a ruling by April 29, said NASA is required to suspend work on the contracts, Reuters reported Thursday.

SpaceX — started by PayPal Inc. co-founder Elon Musk six years ago — is a newcomer to space exploration, having only last year launched its first commercial low-cost rocket. The Falcon 1 was the first among a line of rockets priced at $7.9 million each.

Orbital, the more established company, held a majority stake in MacDonald, Dettwiler and Associates Ltd., developer of the Canadarm technology, from 1999-2001.