The Reserve Bank of New Zealand has agreed to accept $8.7 billion in housing loans as security from the ANZ National and the Westpac banks should they run short of cash.
The banks are the first to take up the Reserve Bank's offer to provide extra liquidity during the global financial crisis.
Westpac says it has not drawn on the facility yet, but may if market conditions remain difficult.
Massey University banking analyst David Tripe says other banks including ASB and BNZ are working on a similar arrangement.
Meanwhile, there are concerns the value of the New Zealand dollar will continue to plunge.
On Friday, it was trading at US59.87 cents but fell to US55.6c on Saturday.
Economist Gareth Morgan says investors are opting out of exotic destinations such as New Zealand.
And he does not think the Reserve Bank's reduction of the Official Cash Rate from 7.5% to 6.5% is related to the drop in the value of the dollar.
Dr Morgan says the markets are still in a state of panic and that consumers can expect to pay more with less credit available.