The Washington Utilities and Transportation Commission wants PacifiCorp and Utah Power & Light Co. to provide more information about their proposed $2 billion merger.

The commission ordered Pacific Power & Light Co., subsidiary of Portland, Ore.-based PacifiCorp, to provide additional information regarding merger benefits to its Washington state customers. It also asked for data about the utility's proposed transmission policy and its effects on other utilities in Washington.The commission believes Pacific Power & Light customers in Washington should be assured they will benefit from reduced costs as a result of the merger, since UP&L ratepayers have been promised an immediate 2 percent rate reduction within 60 days of the merger.

The proposed merger partners say, and the commission agrees, that the consolidation will result in better utilization and more efficient use of power resources and postpone the addition of costly resources. Washington is one of seven states which must approve the deal for it to go through.

Idaho, Wyoming and California have already approved the merger. Decisions are still pending in Utah, Montana and Oregon, as well as Washington.

Federal regulators also have not issued a ruling on the plan.