Shareholders in Z Energy have voted in favour of the company being bought by Australia's biggest fuel supplier, Ampol.

The scheme of arrangement was passed by the required majority of shareholders – 75 per cent or more of the votes cast and more than 50 per cent of the total number of Z Energy shares on issue.

The deal had the support of the Z Energy board.

"Your directors are of the view that the scheme presents the best way forward for Z at this time, given the premium to Z's share price prior to Ampol's approach, the industry headwinds faced by Z over the long term and the certainty provided by the scheme," chair Abby Foote said in a statement.

The offer was pitched at $3.76 a share.

Foote said the board had received proxies representing 63.21 per cent of Z Energy's issued share capital.

Of these, 97.50 per cent were in favour of the scheme.

The deal was last week given the green light by the Commerce Commission.

Z Energy's takeover coincides with the shut-down of Refining NZ's refinery at Marsden Point, which will be converted to a terminal.

Ampol closed one of its own refineries in Australia in 2014.

Now, it places emphasis on its ability to trade in fuel in the energy hubs of Singapore and Houston - and ship it to Australia and New Zealand.

Ampol chief executive Matt Halliday said refinery closures are a sign of the times as refining margins tighten and as the world transitions to renewable energy sources.

At $2 billion, Z Energy is easily Ampol's biggest acquisition outside of Australia.

Z Energy looks set to pass into Ampol ownership after a shareholder vote today. Photo / Supplied

Halliday said the import transition the New Zealand market and Z Energy are working through was key.

"I think there is good complementary [with Z] with some of the skills that Ampol has in terms of the position we have with our trading and shipping business," he told the Herald in a recent interview.

"And from a fuel security point of view, there is more confidence that we can bring to a full-import supply chain."

Halliday says that as the world moves away from fossil fuels, scale will be increasingly important, whether that's in the form of financial muscle or shared capability and experience.

Z Energy listed on the NZX in 2010.