The operating profit of $561million for the year ended June was 7% higher than the previous corresponding period's $523million, and $2million ahead of Forsyth Barr's forecast.
The reported profit of $234million was 27% higher than the $184million in the pcp and $18million higher than forecasts, he said.
The final dividend was 9.1c per share, reflecting the impact of the $50million share buyback the company undertook in the fourth quarter.
''Looking ahead to 2019, Mercury has guided to $515million, based on forecast hydro generation. Our current forecast is $507million, based on a slightly lower hydro generation assumption,'' Mr Foster said.
The Government owns more than half of Mercury. It, and the other 85,000 shareholders, will receive a total dividend for the year of 15.1c per share.
Mercury chairwoman Joan Withers the company was pleased to continue to deliver strong shareholder returns while executing on its strategy that included delivering sustainable growth.
Chief executive Fraser Whineray said key projects during the year included an ICT systems upgrade, completion of Metrix's meter data project upgrade and expanding its ability to provide certified half-hourly meter reads, hydro refurbishments at Aratiatia and Whakamaru stations and major maintenance outages at geothermal stations.
The Mercury brand maintained its trader-churn - customer switching to an alternative retailer - advantage at 6.4% compared to the rest of the market at 8.1%, he said.
''Retail market conditions remain very competitive. However, our brand and customer service activity, focused on inspiring, reward and making things easy for our customers, continues to show strong results.''
In May, Mercury completed the purchase of a 19.99% stake in Tilt Renewables, a company with significant operational and consented wind generation interests in Australasia.
Mr Whineray said the shareholding in Tilt was an extension of Mercury's long-term growth strategy.
It gave Mercury a meaningful interest in significant development opportunities related to Australia's accelerating transition to renewable energy sources and part of Mercury's broader wind strategy.
Building its own platform of projects in Australia would have taken years.
It would learn more about wind and utility-scale solar development as Tilt's projects were developed, and other options for adding value might yet emerge, he said on a conference call.
Mr Whineray noted the firm last week found itself making a joint takeover offer for Tilt in partnership with Infratil, having only bought its initial stake 90 days earlier.
Infratil was an astute and ''very active manager'' and he could see three or four different scenarios for getting additional value from the Tilt portfolio. But how and when they might unfold was hard to say.
''It's not a one-off thing,'' he said. ''Think about it more as a series of chess moves.''
Mercury shares last traded at $3.41. Forsyth Barr had an outperform rating on Mercury as one of its preferred electricity stocks and had a target price of $3.48 per share.
