Fuel prices have risen for the second time in as many days, dousing a long run of reductions which began in October.

National petrol and diesel prices rose 3 cents a litre at the pump today, following a 4c rise yesterday.

A litre of 91-octane lifted to 179.9c, and diesel 113.9c.

Petrol and diesel prices had both fallen nearly 50c a litre as tumbling commodity prices led to a record run of 22 consecutive cuts at the pump.

But a depreciating New Zealand dollar, combined with the first increases to commodity prices since August, have turned the tide on petrol prices.

BP spokesman Jonty Mills said pump prices had increased today after the cost of product rose 4.5 per cent.

"We think the market is rebounding towards a market forecast US$50 (NZ$68.52) barrel price benchmark after falling well below that figure.

"It's another indication of the volatility in the international market."

Automobile Association PetrolWatch spokesman Mark Stockdale said yesterday the 4c hike was "a bit on the nose" for consumers after fuel companies had mostly cut prices by 2c during the latest run.

An industry rule of thumb suggests an US1c fall in the currency corresponds to a 1c rise in the price of fuel.

Over the past week the New Zealand dollar has fallen more than 2c to below US73c, a four-year low, although it did rise as high as US73.22c earlier today.

"While the imported cost of fuel had increased more than a week ago, unusually high fuel company margins had absorbed much of that," Stockdale said.

"But margins have now fallen to levels last seen in April 2014, which means fuel companies had finally passed on all of the commodity price reductions."