SAN FRANCISCO — In the first trial of a wave of class action suits demanding seating for retail cashiers, a federal judge ruled Tuesday that Kmart Corp. does not have to modify checkout aisles to provide seats or pay civil fines for violating a California employment regulation.

But what might seem like a victory for corporate defense lawyers includes a gift for plaintiffs: a possible roadmap to victory in future cases that involve larger classes and more money.

The regulation at issue states “all working employees shall be provided with suitable seats when the nature of the work reasonably permits the use of seats.”

Since 2009 plaintiffs lawyers have targeted retailers, groceries and banks for not providing seats to clerks and cashiers.

Wal-Mart Stores Inc., Target Corp., Bank of America, CVS Pharmacy and Ralph’s Grocery, are all defendants in similar litigation, and three appeals are currently pending before the U.S. Court of Appeals for the Ninth Circuit, with corporate defense lawyers and business groups paying close attention.

After a one-week bench trial last month, U.S. District Judge William Alsup of San Francisco entered judgment for Kmart Tuesday, finding plaintiffs lawyers had not demonstrated any seating arrangement that would allow cashiers at Kmart’s Tulare store to safely perform their job functions.

The judge rejected one solution proposed by plaintiffs lawyers as unsafe, inconvenient and inefficient.

However, Alsup also shared his view of the most practical seating option — a slim stool that employees could rest on, taking weight off their feet, but that would not impede their work.

The fact that Kmart would have to reconfigure checkout aisles and spend money on the modification did not concern Alsup, who wrote the amount would be “in the same ballpark as the fees paid to its ergonomic expert in our trial.”

While it is reasonable for Kmart to expect cashiers to stand while processing customers, that rationale cannot apply to a slow day when the lane is empty and the cashier has run out of tasks, Alsup wrote in his findings of fact and conclusions of law.

The Kmart trial was a test case limited to a single store in California’s Central Valley, and Alsup said he would still consider certifying a broader class of cashiers working in Kmart stores throughout California.

Kmart is represented by Joan Tucker Fife, Amanda Sommerfeld and Robb Adkins of Winston & Strawn and Jeffrey Wohl, chair of Paul Hastings’ employment law practice.

On the plaintiffs’ side are Matthew Righetti and Michael Righetti of Righetti Glugoski; Zachariah Dostart and James Clapp of Dostart Clapp & Coveney in San Diego; and Kevin McInerney of Reno. They’ve teamed up on roughly a dozen suitable seating cases across the state.

Alsup said his order in Garvey v. Kmart, 11-2575, does not necessarily endorse lean-stools, such as those used in Europe.

“To be very clear, this order does not approve or order lean-stools but only notes, that, after hearing all the evidence, lean-stools seem to be the only possible candidate for seating that plausibly would be consistent with the job requirements,” Alsup wrote, adding the evidence would have to be explored in a different trial involving a different class.

At trial, plaintiff’s lawyers proposed adding a more conventional stool to the small cashier area, which would tuck beneath the counter.

However, Alsup said a stool would not slide easily because its legs would catch on a fatigue mat placed on the floor for comfort. Attaching wheels to the stool would be no solution because it would make the seat too unstable, he wrote.

Lawyers for the cashiers also suggested shortening the bagging area to be in arm’s length of a seated cashier. On that point, Alsup concluded the adjustment would interfere by eliminating a corridor for cashiers to move in and out of the customer lane.

The recent claims are brought under California’s Private Attorney General Act of 2004, or PAGA, which allows civil penalties of $100 per employee per pay period for a first violation, and $200 per employee per pay period for subsequent violations. Under PAGA 75 percent of any penalties go into the state treasury for the enforcement of employment laws. Prevailing employees are entitled to 25 percent, with attorney fees and costs paid by the defendant.