Mercury Casualty Co. has lost a court battle to immediately block state Insurance Commissioner Dave Jones’s order to lower its rates by 8 percent for 270,000 homeowner policyholders.

The Sacramento Superior Court denied the company’s petition for a stay that would have delayed implementation of Jones’ order, his office announced on Wednesday. The property/casualty unit of Los Angeles insurance giant Mercury General Corp. will have the opportunity for a later court hearing over its desired 7.3 percent rate increase on homeowner policies.

Mercury Casualty had proposed the increase based on its data about rising loss costs. But Jones countered with an order to drop rates by 8 percent, citing a recommendation by administrative law judge following public hearings on Mercury’s initial rate request.

“We vigorously opposed Mercury’s effort to deny consumers the benefit of a rate reduction while Mercury continues its meritless effort to challenge the insurance commissioner’s established authority to reject excessive rate hikes,” Jones said in a statement.

Mercury said that it looked forward to presenting its full case to the court.

“While we are disappointed with the court’s decision pertaining to the stay, we are pleased the judge recognized Mercury’s ‘compelling arguments’ as they relate to the merits of the rate filing,” the company said in a statement. “Once the Superior Court reviews the evidence, we believe it will reverse the commissioner’s decision and allow Mercury to implement rates that allow a fair rate of return.”

The Superior Court’s decision was applauded by Santa Monica activist group Consumer Watchdog.

“Mercury was given ample opportunity to explain why it needed to raise rates on consumers but their claims did not stand up to scrutiny,” Pamela Pressley, the group’s litigation director, said in a statement.