SAN FRANCISCO (AP) – California’s highest court ruled that country clubs must offer gay members who register as domestic partners the same discounts given to married ones – a decision that could apply to other businesses such as insurance companies and mortgage lenders.

The Aug. 1 decision by the California Supreme Court dealt with a policy at the Bernardo Heights Country Club in San Diego that allowed only the children, grandchildren and spouses of married members to golf for free.

Birgit Koebke, 48, an avid golfer who pays about $500 a month in membership fees, challenged the policy after being told that her longtime lesbian partner could only play as a guest six times a year while paying up to $70 per round.

The court ruled that the policy constitutes “impermissible marital status discrimination.”

While businesses might once have claimed a legitimate business interest for maintaining different policies for married couples and gay and lesbian members who cannot legally wed, such distinctions are no longer justified under a sweeping domestic partner law that took effect in California on Jan. 1, the court said.

“The Legislature has made it abundantly clear than an important goal of the Domestic Partner Act is to create substantial legal equality between domestic partners and spouses,” Justice Carlos Moreno wrote for a five-judge majority. “We interpret this language to mean that there shall be no discrimination in the treatment of registered domestic partners and spouses.”

Koebke greeted the ruling, saying: “We aren’t activists, we aren’t politically charged. We just wanted to play golf together and we just really felt we had every human right to do that.”

John Shiner, the lawyer representing Bernardo Heights, said “the club will take whatever action is necessary to comply with the decision of the Supreme Court.” He would not elaborate on whether that means the club will start giving spousal privileges to the partners of gay and lesbian members.

Jon Davidson, legal director of the Lambda Legal Defense and Education Fund, predicted that the ruling would affect not just country clubs, but mortgage lenders, insurance companies and other businesses that have separate policies or fees for married and unmarried customers.

“What the court said was that if a business in California provides benefits to married couples, it has to provide them equally to couples who register as domestic partners,” Davidson said.

Outside of Massachusetts, where same-sex couples can legally wed, and Vermont, which recognizes civil unions, California offers the nation’s strongest legal protections for same-sex couples.

Under the expanded domestic partner law, nearly 29,000 couples who registered their relationships with the state received nearly the same responsibilities and benefits as married spouses, ranging from access to divorce court to liability for a partner’s debts. Heterosexual elderly couples are also eligible.

Most large employers in California already provide insurance benefits for the same-sex partners of their gay and lesbian workers, while many insurers, hotels and rental car companies have voluntarily extended family-type discounts to gay and lesbian-headed households. Beginning in 2007, all businesses with large state contracts will be required to offer domestic partners the same benefits that spouses enjoy.

Gay rights activists want California to follow Massachusetts’ lead in making marriage an option for gays and lesbians. The high court’s embrace of the notion that domestic partners form families that deserve to be treated like any others may bode well for a lawsuit seeking to overturn California’s ban on same-sex marriage that is now working its way through the courts, according to Davidson.

Rejecting the country club’s claim, for instance, that it limited spousal benefits to married members for the “legitimate goal of creating a family-friendly environment,” Moreno wrote that the domestic partner law, like the state’s marriage laws, “seeks to promote and protect families as well as reduce discrimination based on gender and sexual orientation.”

The ruling, which included a partial dissent from Associate Justice Kathryn Werdegar, reversed two lower courts that sided with the country club. But the court also said that Koebke and Kendall French, 43, who have been together since 1993 and registered partners since 1998, were not entitled to seek damages “for being subject to discriminatory treatment” before the domestic law kicked in.