Clear Channel Outdoor Holdings Inc. is considering whether to appeal a ruling by a state appellate court that would force it and another company to remove more than 100 digital billboards throughout Los Angeles, including in the Valley.

A three-judge panel of the state’s 2nd District Court of Appeal ruled on Monday that Clear Channel, of San Antonio, Texas, and CBS Outdoor Inc., of Phoenix, must take down digital billboards that were erected under what it deemed was an illegal agreement between the companies and the city.

Jim Cullinan, a spokesman for Clear Channel, said the company disagrees with the decision and is reviewing the details of the court’s opinion.

“While this legal process continues to move forward, Clear Channel Outdoor remains focused on delivering great advertising solutions for our customers and working with the city and community of Los Angeles,” said Cullinan, in a statement.

The city allowed the companies to convert up to 840 signs as part of a 2006 legal settlement after Clear Channel and CBS sued to block a 2002 ordinance that would have severely restricted digital billboards.

Summit Media, a smaller Santa Monica billboard company, then filed suit to overturn the agreement on the grounds that the city had shown favoritism to CBS and Clear Channel. A lower court judge agreed that the agreement was illegal, but refused to order the removal of more than 100 signs that had already been converted.

Many of the digital billboards ordered for removal by the appellate court are on the Westside of Los Angeles, but they also are in Studio City, North Hollywood and Woodland Hills.

Philip Recht, an attorney with Mayer Brown LLP in downtown Los Angeles who represents Summit, called the decision a victory for fairness and openness in city government.

“Summit Media expects the city will fully comply with the appellate court’s ruling to revoke the permits that have allowed Clear Channel and CBS Outdoor for over five years to illegally operate 103 digital billboards,” said Recht, in a statement. “The ruling sends a message that the quality of our neighborhoods and the equal enforcement of our laws cannot be ignored for the benefit of a few rich and powerful corporations.

Summit was supported in its lawsuit by neighborhood groups who complained the signs were a blight that lit up their neighborhoods with constantly changing images.