The law firm that successfully represented Edison International workers in their 401(k) fee lawsuit wants a federal appeals court to allow it to recover nearly $1 million in fees for expert witnesses used during the 11-year litigation.

Schlichter Bogard & Denton LLP’s move comes after a federal judge in California rejected its expert fee request because it didn’t identify which of the expert’s work was “crucial or indispensable” to their only successful claim: that the Edison plan didn’t offer the...