The Reserve Bank of New Zealand on Monday announced changes in the way it calculates the domestic currency's trade-weighted value to better reflect its growing trading ties with China, while cutting the share of U.S. dollars, euros and yen.
As of Wednesday, the Australian dollar will comprise 21.98 percent of the index, the largest proportion and rising from 21.61 percent now, while the Chinese yuan will be added to make up 20.09 percent.
The increase in the Australian dollar's weighting and the inclusion of the yuan reflect the impact that the values of those currencies have on the "kiwi" dollar given that Australia and China are New Zealand's two largest trading partners.
The British pound and the yen will also see their weightings reduced to make room for the currencies of Singapore, South Korea, Malaysia and nine other mainly Asian units, highlighting the South Pacific island nation's trading ties with Asia.
The trade-weighted index climbed to a post-float high around 82.03 earlier this year, boosted by a rise in New Zealand interest rates and a strongly performing economy.
It has since eased to trade at 78.19 on Monday, having gained 0.8 percent so far this year.