SAN FRANCISCO  The California Supreme Court ruled Monday that privately owned shopping malls cannot stop protesters from demonstrating there to urge a boycott of one of the tenants.

In a 4-to-3 decision, the court said a San Diego mall violated California law protecting free speech when its owners barred protesters from distributing leaflets in front of one of the mall’s stores, asking shoppers not to give the store their business.

“A shopping mall is a public forum in which persons may reasonably exercise their right to free speech,” Justice Carlos R. Moreno wrote in the majority opinion.

Justice Moreno said shopping malls were entitled to enact and enforce “reasonable regulations of the time, place and manner of such free expression,” to avoid a disruption of business.