The Bonneville Power Administration will favor its preferred customers over measures designed to help threatened and endangered salmon and steelhead when it distributes $500 million in surplus revenue.

On Friday, BPA administrator John L. Hairston announced the agency would devote $350 million of the unexpected revenue last year to reducing the cost that its contracted customers pay for wholesale power. The agency will use $100 million to pay down its debt and $50 million to supplement its fish and wildlife program. The spending formula is unchanged from one proposed in November.