The New Zealand dollar is more than half a cent lower against both the US and Australian dollars.
ASB Bank head of external foreign exchange sales Tim Kelleher said Wednesday's sell-off accelerated overnight.
"We saw some very heavy selling on the London open last night, which was a combination of further disappointment on the Fonterra numbers, even though they were on expectations, and the business confidence being weaker as well.
"So what we saw was some mature longs that had been around for probably a number of months finally getting out of their positions," he said, referring to investors who expect the currency will rise.
"That's fed through to today, and we've seen some further weakness in the markets this morning but we're getting to some levels where medium-term we've seen some buyers previously."
Just after 5pm, the New Zealand dollar was buying: 84.78 US cents, 91.37 Australian cents, 50.7 pence, 0.6234 euro, 86.26 yen and 5.30 renminbi.
Shares little changed
New Zealand shares were little changed on Thursday, the benchmark Top 50 Index edging up 2 points to 5183.
Craigs Investment Partners head of wealth management Mark Lister said the weaker currency was helping some stocks.
"That's helped the likes of Fisher and Paykel Healthcare, which has had quite a good run this month."
Fisher & Paykel shares gained 6 cents to $4.49 but shares in Pacific Edge - which had been one of the stars of the New Zealand market during the past year - fell 3 cents to 86 cents.
Mr Lister put that down to its recent result announcement, which had reminded people some of the initiatives they were taking were quite long dated and would not necessarily lead to high profits in the short term.
"It's a good long-term story but I think it's a bit of a reality check," he said.
Units in the Fonterra Shareholders' Fund rose 3 cents to $6.06 following its forecast and record payout announcement on Wednesday.