Opec will cut its production by 1.5 million barrels per day for the next six months.
Saudi Arabian Oil Minister Ali al-Nuaimi announced the cut in production, which starts from January 1st.
The price of oil has tumbled on commodity markets due to lower demand after the September 11th attacks and a build-up of capacity among the world's major suppliers.
The move is intended to bolster the price of crude oil but is seen as likely to increase prices.
Mr Garry Russell, co-ordinator of the "Dump the Pump" campaign, is warning that petrol prices in the UK could now rise to as much as 80p per litre over the next six months.
"It's in the major oil producing countries' interest to restrict the flow of their product and I'm sure petrol prices will go back up again."
Industry experts dismissed the threat of impending price increases at the pump and said the impact of the production cuts on petrol would be negligible.
Oil prices have fallen to as low as $16 a barrel from their peak of $35 in November last year. News of the impending production cut has seen the current price get to as high as $21.
PA