By David Shepardson

WASHINGTON (Reuters) -A U.S. government watchdog on Friday sided with NASA over its decision to pick a single lunar lander provider, rejecting a protest filed by Blue Origin and defense contractor Dynetics Inc.

The companies had challenged the $2.9 billion award to Elon Musk’s SpaceX for the lander, arguing NASA was required to make multiple awards. The Government Accountability Office (GAO) said it “denied the protest arguments that NASA acted improperly in making a single award to SpaceX.”

Blue Origin, the rocket company founded by billionaire Jeff Bezos, said Friday it remained convinced that there were “fundamental issues” with NASA’s decision, but said it believed GAO was not able to address them “due to their limited jurisdiction.”

“We’ll continue to advocate for two immediate providers as we believe it is the right solution,” Blue Origin said.

SpaceX did not comment but Musk sent a tweet saying just “GAO” with a flexed muscle emoji.

Dynetics, a unit of Leidos Holdings, did not immediately comment.

NASA had sought proposals for a spacecraft that would carry astronauts to the lunar surface under its Artemis program to return humans to the moon for the first time since 1972.

In April, NASA awarded https://www.reuters.com/technology/spacex-wins-us-contract-spacecraft-send-astronauts-moon-washington-post-2021-04-16 SpaceX a contract to build such a spacecraft as early as 2024.

Blue Origin had contended NASA gave SpaceX an unfair advantage by letting it revise its pricing.

On Monday, Bezos offered to cover up to $2 billion in NASA costs if the U.S. space agency awarded Blue Origin a lunar landing contract.

In a letter to NASA Administrator Bill Nelson, Bezos said Blue Origin would waive payments up to $2 billion, and pay for an orbital mission to vet its technology. In exchange, Blue Origin would accept a firm, fixed-priced contract, and cover any system development cost overruns.

“Without competition, NASA’s short-term and long-term lunar ambitions will be delayed, will ultimately cost more, and won’t serve the national interest,” Bezos said.

Bezos’ offer came six days after he flew alongside three crewmates to the edge of space aboard Blue Origin’s rocket-and-capsule New Shepard.

(Reporting by David Shepardson; Editing by David Gregorio and Rosalba O’Brien)