March 19 (Bloomberg) — Fidelity Management Trust Co. and the U.S. unit of generator-maker ABB Ltd. won an appeals court decision that upends a trial judge's finding that breaches of their legal obligations cost ABB retirement plan participants more than $35 million.

A 2-1 majority of the U.S. Court of Appeals in St. Louis ruled Fidelity had no obligation to recapture for plan participants $1.7 million in overnight "float" income because the funds weren't a plan asset as defined by federal law. The panel unanimously agreed ABB breached its duty by failing to monitor plan record-keeping costs.

Still, the appeals court faulted U.S. District Judge Nanette Laughrey's methods for computing damages and returned the case to her Jefferson City, Missouri, court for further consideration. The judge's 2012 ruling came after a 16-day trial without a jury.