Judges in a Northwestern state say the top insurance regulator there had the authority to block efforts by a nonprofit health plan to shift to for-profit status.

The 3 members of a Washington state appellate court panel agreed unanimously to uphold a July 2004 ruling by state Insurance Commissioner Michael Kreidler.

In 2004, Kreidler said he believed the proposed Premera conversion would hurt subscribers and the insurance-buying public.

The ruling rejected a conversion application filed by Premera Blue Cross, Mountlake Terrace, Wash.

Premera argued that Kreidler exceeded his authority and misinterpreted the law, but the appellate court judges sided with Kreidler.