Wellington, Dec 2 NZPA - Electricity networks company Powerco is "cautiously optimistic" after the Commerce Commission published its decisions on prices and quality in the industry.

The commission's decisions will apply to electricity distribution businesses from April 1, allowing prices to be increased by the rate of inflation while ensuring the quality of supply to consumers is maintained.

Powerco today said it remained positive that any initial price adjustment would not detract from investment that was likely to result from the commission's determination.

The commission would not release a decision on whether an initial adjustment was needed until the end of 2010, Powerco said.

Powerco regulation and business manager Paul Goodeve said it had been working closely with the commission to contribute to a sustainable regulatory regime which ensured electricity consumers.

Expectations around price and quality were met while improving certainty around infrastructure investment.

Powerco was cautiously optimistic about the future of regulation, following the commission's determination, Mr Goodeve said.

While work needed to be done in the regulatory area, recent signs of improvement had improved Powerco's outlook, compared to its view three to four years ago.

Powerco's electricity networks supply more than 314,000 customers in Wairarapa, Manawatu, Wanganui, Taranaki, Western Bay of Plenty, South Waikato, Hauraki Plains and Coromandel.