New Zealand shares fell on Wednesday as investors awaited the country's gross domestic product numbers for the second quarter along with the US Fed's interest rate decision.

The S&P/NZX 50 index was down 0.67%, or 84.97 points, to close at 12,586.98.

The country's economic performance for the second quarter will be announced on Thursday, with analysts expecting a decline in activity. The Trading Economics consensus forecast is for a 0.4% decline in GDP, following a 0.2% expansion in the prior three-month period.

In other macroeconomic news, New Zealand's current account deficit widened by NZ$269 million to NZ$7.2 billion in the June quarter due to a higher shortfall in primary income and goods, Stats NZ said in a report on Wednesday.

The country's consumer sentiment index rose 9 points to 90.8 in the September quarter, showing continued low confidence albeit a slight uptick in optimism about the nation's economic outlook, according to Westpac's McDermott-Miller report.

In contrast, farmer confidence reached net positive levels for the first time since late 2021, according to a spring survey by agribusiness bank Rabobank.

In corporate news, New Zealand's Commerce Commission will file charges against Qantas Airways (ASX:QAN) subsidiary, Jetstar, for allegedly misleading consumers about their compensation rights when flights were delayed or canceled.

Synlait Milk (ASX:SM1, NZE:SML) shareholders approved three resolutions, allowing a debt reduction via the issue of around NZ$217.8 million in new equity to the company's two largest shareholders Bright Dairy Holding and a2 Milk (NZE:ATM, ASX:A2M). Synlait shares were down more than 4% at market close.