"We expect that net immigration will remain strong over the coming year, approaching a net inflow of 60,000," Westpac Banking Corp New Zealand senior economist Satish Ranchhod said in a note.
"The weak Australian economy is keeping New Zealanders at home. At the same time, New Zealand's strong economic outlook is continuing to draw in foreign workers in historically very large numbers."
Still, Ranchhod noted the monthly increase in net immigration appeared to have stalled, with net immigration falling to a seasonally adjusted 4,740 in April from 4,990 in March as the arrival of non-New Zealand citizens eased off.
A decline in migrant departures reflects fewer people leaving for Australia, where the economic prospects are weaker following a slowdown in the mining industry.
New Zealand had a net inflow of 100 migrants from Australia in April, the first month the country has had a net gain from Australia since 1991.
On an annual basis, the country had a net loss of 1,900 people to Australia in the year through April, the smallest since 1992.
The gain in migrant arrivals was driven by India, with a net gain of 12,200 people in the year through April, followed by 7,800 from China, 4,600 from the UK and 4,000 from the Philippines.
About three-quarters of migrants from India and half of migrants from China arrived on student visas, the agency said.
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