(Reuters) - A U.S. appeals court made it easier on Monday for day laborers to find work in Arizona, upholding an injunction that bars the state from enforcing part of its immigration law that prohibits motorists from stopping traffic to pick up workers.

In the ruling, a three-judge panel of the San Francisco-based U.S. Ninth Circuit Court of Appeals upheld a decision by a district judge who granted a preliminary injunction against the provision of the 2010 state law.

"Laws that limit commercial speech must not be more extensive than necessary to serve a substantial government interest," Ninth Circuit Judge Raymond Fisher wrote in his opinion upholding the injunction.

The Arizona law went too far in restricting the commercial speech between day laborers and motorists looking to hire them, Fisher wrote.

(Reporting by Alex Dobuzinskis; Editing by Cynthia Johnston)