WELLINGTON, New Zealand--Meridian Energy Ltd. inflated New Zealand power prices in December by unnecessarily spilling water from its southern hydro dams, the electricity market regulator said in a preliminary decision.

Offer prices into the electricity market from Meridian's dams were higher than they should have been during a period of heavy rainfall and flooding in December, the Electricity Authority said on Tuesday.

Seven electricity retailers had complained about Meridian Energy and Contact Energy Ltd., but the regulator said Contact's activities in isolation didn't constitute an "undesirable trading situation."

Meridian said in a statement that it experienced extremely high inflows of water into its reservoirs in December and had to "manage these exceptional weather events in real time."

The regulator said it will receive submissions on its preliminary decision until August 11. 



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