Fuel retailer Gull has committed to not increase prices at its outlets until the end of the week.
The moves comes after an attack on Saudi Arabian oil fields led to large spike in the price of oil - and warning petrol in New Zealand could surge to up to $3 a litre
Gull chief executive Dave Bodger said local fuel prices usually followed prices in the international market.
"The long-held rule of thumb of a $US1 increase in the price of a barrel of crude oil equates to a cost increase of 1 New Zealand cent per litre still holds," he said.
International refined fuel prices in Singapore rose by about US$6.50 per barrel for petrol and US$5.50 per barrel for diesel overnight.
Gull estimated that with the current exchange rate this would lead to a 6.5 cents lift in the price per litre of petrol and a 5.5 cents increase for diesel.
"We will monitor the situation daily," Bodger said.
"We appreciate that any price increase is a major blow for Kiwi motorists, and we will minimise and delay this as much as possible."
New Zealand's other major petrol retailers have also not lifted prices at this stage.
Yesterday, Z Energy chief executive Mike Bennetts said he was monitoring the situation and that the impact of the attacks would likely only be felt in the short term.
"Oil in storage is quite high at the moment, so if this was to go on for a week or so it could be easily managed," he told Mike Hosking Breakfast on Newstalk ZB.
"If it's a short-term disruption, it's probably worth up to $5 a barrel, or about 5 cents a litre at the pump.
"If it's a more long-term disruption, we could be looking at something around $10 a barrel, or 10 cents a litre."
BP spokesman Gordon Gillan wouldn't speculate on how much prices would rise but did confirm that an increase could happen within the next day or two.