Auckland-based Mercury has swapped its Roman god logo for a bee.
Mighty River Power - the listed generator that is part of the company - has also been branded Mercury with a new share market ticker code.
Chief executive Fraser Whineray said the change signals a new era of benefits for Kiwi consumers and the country from renewable energy and rapid advances in technology.
Extensive market research with customers showed very strong engagement with Mercury's new direction and the new 'bee' logo, Whineray said.
"We chose the bee to symbolise all the wonderful things we want to be and do for New Zealanders. The bee is Kiwi to the core. It's optimistic, energetic and quietly busy making the world a better place,'' .
"Like our bee, renewable electricity is natural and essential to the planet, promoting well-being and real sustainability for future generations."
Developing the logo cost in the low six figures and the entire rebrand across the company was in the low millions of dollars, said Whineray.
There were ''huge amounts'' of customer and stakeholder research.
The old logo dated back to Auckland Electric Power Board days and was not distinctive, said Whineray. There was also confusion between the Mighty River Power which has around 93,000 shareholders and Mercury brands.
Asked if there was a danger of associating bees and being stung with power bills, Whineray said this hadn't come up in market research.
''If you go and touch electricity like touching bees that's not going to do you any good either. But just like what a bee does for the world, electricity is remarkably important. Don't touch it but do use it.''