The case is at the Supreme Court amid intensified scrutiny of fees in retirement accounts, now the primary savings vehicle for old age. More than a dozen companies, including Lockheed Martin Corp. and ABB Ltd., have been sued since 2006. Lockheed last week settled its case for $62 million. Americans held $6.6 trillion in 401(k)-type plans as of Sept. 30, according to the Investment Company Institute.

A federal appeals court said the Edison workers could sue only over three funds that were added to the plan within the six-year time limit to file a lawsuit. The workers won $371,000 on those funds and say they are entitled to additional damages on funds added earlier.

Little Support

The appeals court’s reasoning drew little support in the hour-long hearing. The justices instead focused on what standards should apply when plans continue to hold old investments.

Edison’s lawyer, Jonathan Hacker, said he agreed with the workers that funds must periodically monitor investments, even those added more than six years earlier. Hacker instead argued that the Edison workers had failed to show that the company’s monitoring was inadequate.

Also read: Supreme Court could redefine ERISA

Justice Anthony Kennedy balked when Hacker argued that plan trustees don’t have a legal duty to be on constant lookout for cheaper investments.

“You certainly do if that’s what a prudent trustee would do,” Kennedy said.

Performance, Expenses

The workers’ lawyer, David Frederick, said plans have a duty to periodically look at the performance, expenses and management of the funds offered to investors. The Obama administration is backing the workers.

The Edison workers say that some of the fees on the retail shares were returned to Edison’s service provider, ultimately reducing the company’s administrative costs by $8 million.

Justices Sonia Sotomayor and Stephen Breyer signaled they would prefer to return the case to a lower court to decide how rigorous a plan’s monitoring must be.

“I, for one, am not ready to do that because I’m not a trier of fact for what a reasonable investor would do,” Sotomayor said.

The justices will rule by the end of their nine-month term in late June.

The case is Tibble v. Edison International, 13-550.

--With assistance from Margaret Collins in New York.

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