The bank branch in Auckland's Queen Street was "filled with carbon bubbles" by protesters from the 350 Aotearoa group, which urged ANZ to divest its fossil fuel interests.
350 Aotearoa then presented staff with a letter requesting that ANZ pull its sponsorship from the summit.
The group says ANZ has admitted that climate change poses a significant risk to its customers, but continues to invest in fossil fuels.
"At a time when scientists agree that we must leave 80% of known fossil fuel reserves in the ground to avoid catastrophic climate change, 350 Aotearoa believes that it is ethically and financially irresponsible for ANZ to sponsor the Petroleum Summit, an event promoting fossil fuel extraction," the group says on its website.
It believed that banners in the street, and balloons in its bank branch will help win over management for the $100 billion company in Melbourne, Australia.
350 Aotearoa recently launched its Fossil Free Banks campaign as part of the global divestment movement, campaigning for banking options in NZ have no investments in fossil fuels and do not lend to the fossil fuel industry.
The divestment movement has already spread in NZ, the Us, Australia, and Canada, primarily religious, educational, and financial institutions.
It is believed 70 global investors, managing over $3 trillion of assets, and have demanded the oil, gas and coal companies asses the risks that climate change poses to their business plans.
350 Aotearoa is joining Greenpeace New Zealand, KASM, and Oil Free Auckland in organising a public march to oppose the Petroleum Summit on Sunday, the first day of the event at which Anadarko, OMV, Todd Energy, Tag Oil, New Zealand Oil & Gas, Randall C. Thompson, LLC and Hyundai Hysco, ex-Greymouth Petroleum director John Sturgess and Mosman Oil and Gas will open the first day of the conference by highlighting possible joint venture opportunities.
The conference aspect kicks off the next day, and will be opened by NZ Resources Minister Simon Bridges.
The conference is being held at Auckland's SkyCity Hotel between March 29 and March 31, and will see the launch of the NZ government's 2015 Block Offer.
Oil is one of NZ's biggest exports, although much of the nation's energy is generated from hydroelectricity.
