New Zealand shares closed flat with a negative bias on Monday as the Asian markets struggled with elevated oil prices amid the US-Iran conflict.

The S&P/NZX 50 Index was little changed to close at 13,147.72.

The Trump administration plans to declare as early as within the week that multiple countries have agreed to form a coalition to escort ships through the Strait of Hormuz along the Iranian coast, according to a Monday Wall Street Journal report, citing US officials.

In domestic news, New Zealand's year-on-year housing market value remained flat in February, decreased in Auckland by 1.1%, and increased outside Auckland by 0.7%, according to the REINZ House Price Index.

Further, New Zealand's services sector fell back into contraction in February, highlighting a slower-than-expected economic recovery, according to a statement by BusinessNZ.

Also, New Zealand's electronic card spending rose 1.1% month over month to NZ$9.69 billion in February on a seasonally-adjusted basis, following a 0.7% decline in the previous month, according to data from Stats NZ

In corporate news, KMD Brands (ASX:KMD, NZE:KMD) confirmed it has appointed Goldman Sachs to provide guidance on treasury and capital management amid a review of funding options.

Chorus (ASX:CNU, NZE:CNU) launched its "Equity Fibre 100" wholesale product, retail capped at NZ$30 per month, which delivers fiber broadband internet connectivity at 100/20 megabits per second, targeting consumers looking for an affordable option.