LOS ANGELES (AP) — Union members can picket privately owned walkways in front of stores, but other protesters, handbill distributors and petition-signature collectors may not, the California Supreme Court ruled.

In the case that pitted Ralphs Grocery Co. against United Food and Commercial Workers Union Local 8, the justices on Thursday struck down an appellate court opinion that found two state laws that protect labor pickets as unconstitutional.

In its ruling, the majority of the state high court noted that privately owned areas in front of stores do not constitute public forum for any type of free-speech activity, but peaceful labor activities related to that retailer are permitted under both state and federal law.

Laws rightfully single out labor-related content for special protection under free speech laws because labor is part of an economic situation, the court said. Picketing outside the employer's premises is an intrinsic part of a labor relationship and free speech, the court said.

"Therefore, it is well settled that statutory law — state and federal — may single out labor-related speech for particular protection or regulation, in the context of a statutory system of economic regulation of labor relations, without violating the federal Constitution," the court said.

In concurring opinions, other justices wrote that retailers had the right to limit picketers so customers are not disturbed, including noise, and the number and size of signs.

The case stemmed from a picket by members of the United Food and Commercial Workers Union who were encouraging shoppers to boycott a Sacramento Ralphs supermarket because its employees weren't unionized.

The grocer went to court in 2008 to remove the picketers, who had been in front of the store several times a week since it opened in 2007.

A court denied the retailer's petition for an injunction citing state laws protecting labor pickets on employer property, but an appellate court overturned the decision, saying the laws were unconstitutional because they gave special protection to labor speech. The union appealed to the Supreme Court.

In a statement, the San Francisco law firm for Ralphs Grocery Co. said that although the high court's decision was not a win, it clarified rules about labor union activity.

"No demonstrator has a constitutional right to be on any retailers' property," said Morrison & Foerster. "And all other demonstrators may be denied access to areas that are not designed to encourage shoppers to congregate."