SAN FRANCISCO — A federal appellate court on Monday gave its blessing to a massive settlement that Volkswagen AG reached with customers to settle claims related to its “clean diesel” scandal.

The U.S. Court of Appeals for the Ninth Circuit found that U.S. District Judge Charles Breyer of the Northern District of California “more than discharged” his duty to ensure that the $10 billion settlement was fair and adequate to the class. As part of the deal, VW agreed to buy back or provide fixes for 2009–2015 model year 2.0-liter diesel cars what had so-called “defeat devices” allowing them to cheat emissions tests.