The Reserve Bank is ramping up support for businesses and banks by accepting corporate debt and other assets as security for loans to banks.
The latest measure is designed to pump more money into the economy through the banking system.
Assistant governor Christian Hawkesby said the aim is to encourage banks to keep funding corporate clients by swapping the company securities they hold for loans for cash from the central bank.
"By banking the banks, we are ensuring large businesses can better manage their cash flows, and lower their funding costs."
The RBNZ will have a weekly window for retail banks to access the money, with an offer to lend around $500 million each time for up to three months.
The programme will run for up to 12 months but end sooner depending on demand.
Hawkesby said other assets would also be accepted for swapping for cash.
The new programme is the latest in a series of measures aimed at holding down interest rates, ensuring liquidity in financial markets to stop volatility and price spikes, and pumping money into the economy to support lending and businesses.