WASHINGTON (REUTERS) - A federal appeals court on Friday rejected President Barack Obama's "recess" appointments to a labour board last year, saying they were constitutionally invalid.

The appointments to the National Labour Relations Board were made while the Senate was out of town but potentially available to act on them.

"Considering the text, history, and structure of the Constitution, these appointments were invalid from their inception," the panel said.

Mr Obama also used such a "recess" appointment early last year to install Richard Cordray as head of the Consumer Financial Protection Bureau, but the court's ruling did not specifically address his appointment.