Mercury lifted its operating earnings by 6% to $523million and its report profit by 15% to $184million in the year ended June.
A final ordinary tax-paid dividend of 8.8c per share would be paid on September 29, along with a special tax-paid dividend of 5c per share on the same date.
Genesis reported an operating profit down 1% to $33million, a 36% fall in reported profit to $119million but an improved dividend of 16c per share.
Forsyth Barr broker Damian Foster said Mercury's result was largely in line with expectations but the cash returns in the form of a special dividend were well ahead of forecasts.
Strong hydro generation had been the main driver of the record result and had enabled Mercury to announce the ''significant'' 5c per share special dividend.
The other factor enabling the special dividend had been carbon credit sales.
It appeared Mercury had finally exited its ill-fated Chile geothermal experiment with an $18million impairment charge.
Looking ahead to 2018, Mercury had given guidance of an operating profit of $500million, which was at the bottom end of the consensus, he said.
Forsyth Barr had a forecast of $502million.
Mercury was assuming 4150GWh of hydro generation, slightly ahead of average.
Capital expenditure guidance was again elevated at $115million versus a long-run expectation of $75million. Mercury was pointing to hydro station refurbishment work and a couple of large IT projects, Mr Foster said.
''It will be interesting to see how the market reacts to the result. The result is a good one but it is in line with market expectations. Guidance appears a little softer than the market expected and capex higher than ongoing maintenance capex.''
The result from Genesis, while in line with expectations, was disappointing, he said.
Operating earnings for the energy division (non-Kupe earnings) were down $7 million, despite favourable operating conditions during the year and a small contribution from the Nova lpg business acquired towards the end of the financial year.
Guidance for an operating profit between $345million and $365million for 2018 was in line with Forsyth Barr's current forecast.
Genesis was claiming $15million to $20million of new ''growth operating expenditure'', although most of it appeared to be ongoing - more people, marketing and customer retention investment.
Capex was expected to be between $50million and $60million, compared to Mr Foster's forecast of $46million.
''Overall, this result is in line with expectations but disappointing given the positive backdrop. The refreshed strategy has yet to pay dividends, although Genesis appeared optimistic it can still meet its medium-term targets.''
Genesis accounts showed net debt was up $379million on the same period as borrowings were used to fund the Kupe and Nova Energy lpg distribution transactions. Debt included the issue of an eight-year $100million wholesale bond and a 30-year $225million capital bond which increased the average debt tenure to 11.4 years. Average cost of debt fell to 5.7%.
Mercury chief executive Fraser Whineray said the response to Mercury's rebranding 12 months ago had been positive.
Mercury grew its overall customer base by 16,000 to 392,000. Total customer base at 17.8% was lower than the marker average of 20.5%. Trader churn, when a customer changed retailer without moving house, was 5.7% against a 7.1% market average.
The Mercury brand also achieved its best residential customer satisfaction score of 64% highly satisfied (three-month rolling average) compared with 60% in 2017, he said.
