The balance of payments summarises all of New Zealand's transactions with the rest of the world.
ASB economist Jane Turner said technical details provided yesterday by Statistics New Zealand showed the current account would be affected by the inflow of foreign insurance payments - largely from reinsurers.
That would affect the transfers component of the balance of payments.
From Treasury estimates of the damage bill, Ms Turner estimated the foreign insurance component to be in the range of $1 billion to $1.5 billion.
The final figure would depend on how comprehensive the cover was for commercial buildings and businesses.
"Imports may also be boosted slightly as households and businesses replace broken goods and as some materials are imported for the reconstruction phase.
We expect exports to be unaffected, with the possible exception of inbound tourism."
Overall, the net effect was likely to be a smaller than otherwise current account deficits in the three months ended December 2010 or March 2011, she said.
The financial account would also be affected.
The Earthquake Commission indicated that some of its capped $1.5 billion payout would come through selling foreign shares - about 30% of its $5.6 billion in assets.
That would reduce New Zealand's holdings of foreign assets.
Any sales of its New Zealand bond holdings could be partially bought by foreign investors, Ms Turner said.
The Government was likely to pick up the bulk of the public-sector damage bill and the cost of emergency measures which, in total, could reach $1 billion.
"If the Government's borrowing requirements were to increase by that amount, potentially half could be bought by foreigners, the majority holder of New Zealand government bonds."
The financial account could conceivably register over time an inflow of $1 billion to $1.5 billion through repatriated proceeds from selling shares and through added sales of government debt to foreigners.
New Zealand's net foreign asset position would decline to reflect the fall in asset holdings and increased indebtedness.
Statistics NZ figures released yesterday showed the annual current account widened to 3% of GDP (gross domestic product) in the three months ended June after narrowing sharply during the past year.
The wider deficit largely reflected cyclical factors with the recovering economy contributing to stronger profitability of foreign-owned New Zealand business.
Also contributing to the wider deficit in the quarter was a deficit in the transfers balance due to a change in non-resident withholding tax policy and a deficit in the services balance due to weak tourism exports.
Providing some offset was a strong trade surplus due to the recovery in global dairy prices since the start of the year.
The June deficit was $880 million compared with market expectations of $500 million.
