May 3 (Reuters) - A U.S. appeals court has temporarily

blocked a National Labor Relations Board case accusing SpaceX of

illegally firing engineers who criticized CEO Elon Musk, as the

rocket company pursues a legal challenge to the agency's

structure.

In a single-sentence order on Thursday, a three-judge panel

of the New Orleans-based 5th U.S. Circuit Court of Appeals

barred the NLRB from proceeding with the administrative case

pending SpaceX's appeal of a judge's "effective denial" of its

motion for an injunction.

The 5th Circuit twice rejected SpaceX's bid to overrule a

decision by U.S. District Judge Rolando Olvera in Brownsville,

Texas, to transfer the case to California at the NLRB's request.

SpaceX then asked Olvera to reconsider the transfer and take

up its motion for a preliminary injunction pending the outcome

of its lawsuit. The company this week filed an appeal, saying

Olvera's delay in deciding that motion amounted to a denial of

it.

SpaceX in its lawsuit claims the NLRB's in-house enforcement

proceedings violate the U.S. Constitution in various ways and

that administrative judges and board members are improperly

insulated from removal by the president. Amazon.com ( AMZN ), Starbucks ( SBUX )

and Trader Joe's have all raised similar arguments in pending

board cases.

An NLRB spokeswoman declined to comment on the 5th Circuit

order. SpaceX did not immediately respond to a request for

comment.

In the underlying board case, SpaceX is accused of firing

eight engineers who signed onto a letter to company executives

accusing Musk of sexism and other misconduct. The company has

said the workers' actions were disruptive and not protected by

federal labor law.

SpaceX sued the NLRB a day after the agency issued the

complaint in January, and has since filed a similar lawsuit in

Waco, Texas, federal court stemming from a separate board

complaint involving the company's severance agreements.

Thursday's 5th Circuit order will likely delay a ruling by a

special master on challenges to subpoenas in the administrative

case, which is pending before an administrative judge in Los

Angeles, and could push back hearings that were slated to be

held in the case over the summer.

The 5th Circuit panel includes Circuit Judges Jerry Smith

and Andrew Oldham, appointees of former Republican presidents

Ronald Reagan and Donald Trump, respectively, and Carl Stewart,

who was appointed by Democratic former President Bill Clinton.

The case is Space Exploration Technologies Corp v. NLRB, 5th

U.S. Circuit Court of Appeals, No. 24-40315.

For SpaceX: Michael Kenneally, Catherine Eschbach, Harry

Johnson and Amanda Salz of Morgan Lewis & Bockius

For the NLRB: David Boehm

Read more:

SpaceX asks Texas judge to block NLRB case over severance

agreements

SpaceX loses latest bid to keep lawsuit against NLRB in

Texas

SpaceX faces hearing on engineers fired after criticizing

Elon Musk over sexism

SpaceX illegally fired workers critical of Elon Musk, US

labor agency says

Amazon ( AMZN ) joins companies arguing US labor board is

unconstitutional

SpaceX loses bid to keep challenge to NLRB structure in

Texas court

(Reporting by Daniel Wiessner in Albany, New York)