By Daniel Wiessner

A U.S. appeals court on Wednesday blocked a California law banning gun marketing that is attractive to minors, saying it was unlikely to reduce gun violence or the unlawful use of firearms.

A panel of the San Francisco-based 9th U.S. Circuit Court of Appeals said hunting and sport shooting groups were likely to prevail on claims that the law violates their free-speech rights under the First Amendment of the U.S. Constitution, and blocked it pending the outcome of the case.

The court reversed a January ruling by a federal judge in Sacramento who had said the law properly regulated commercial speech and the groups were unlikely to succeed in their challenge.

California Governor Gavin Newsom, a Democrat, signed the measure into law last year, citing the need for new legislation "as the (U.S.) Supreme Court rolls back important gun safety protections."

Newsom's office cited gun manufacturer Wee 1 Tactical's advertising of an AR-15 meant for kids as an example of why the law was needed.

(Reporting by Daniel Wiessner in Albany, New York; Editing by Alexia Garamfalvi and David Holmes)