The Supreme Court heard arguments this week in a case that could reshape how employers manage roughly $12 trillion in U.S. retirement savings, with several justices appearing reluctant to let a lawsuit against Intel proceed over its decision to place private equity and hedge fund investments in its 401(k) plan.

At issue is whether Intel plan participants can sue the company for breach of fiduciary duty under the Employee Retirement Income Security Act after the funds underperformed conventional index options. Intel has argued that ERISA requires plans to offer a diversified menu and that the investments were disclosed to participants, who chose them voluntarily.

The case carries immediate stakes for millions of workers whose employers are watching the outcome before deciding whether to add private equity to their own retirement menus. Plan sponsors have been in limbo, waiting on both the Supreme Court ruling and finalized Labor Department rules covering private fund allocations in defined-contribution plans.

Several justices pressed the plaintiffs' attorney on where the line between poor performance and legal breach should be drawn, noting that ERISA does not guarantee investment returns. The questioning suggested a majority may be inclined to set a higher bar for such claims, potentially shielding employers from suits over fund selection when proper disclosures were made.

Intel's plan at one point held more than $1 billion in hedge fund and private equity allocations, according to court filings. The plaintiffs contend the company paid excessive fees and took on unnecessary risk compared with low-cost alternatives, while Intel maintains the plan's overall performance was competitive.

Business groups including the U.S. Chamber of Commerce have backed Intel, warning that allowing the suit would make employers reluctant to offer any nontraditional investment options. Consumer advocates counter that without the threat of litigation, plan sponsors face little accountability for steering workers into costly, poorly performing funds.

"I think companies want to know what's going to happen with the proposal and what's going to happen" with the litigation, one industry attorney said during arguments, reflecting the twin uncertainties facing plan administrators.

A ruling is expected by the end of the court's term in June. Whatever the outcome, the decision will land alongside the Labor Department's pending rule on private fund disclosures, which could take effect as early as this year and would add new reporting requirements for plans that include such investments.

The case originated in the U.S. Court of Appeals for the Ninth Circuit, which allowed the participants' claims to move forward. Intel had asked the Supreme Court to reverse that ruling, arguing that ERISA fiduciaries should not be second-guessed for investment decisions made with proper process and disclosure.