Oil rose above $74 a barrel today amid persistent fears about supply disruption and aggressive fund-buying across the commodities sector.
US light, sweet crude rose 47 cents to $74.17 a barrel by 9am Irish time, while London Brent crude gained 41 cents to $74.30.
Prices are close to the record high of $75.35 for US crude touched in April, which was largely driven by concern Iran's stand-off with the West over its nuclear programme could lead to disruption of its oil output.
UN ambassadors from the United States, Britain and France are expected this week to introduce a Security Council resolution to make Iran, the world's fourth biggest oil exporter, comply with demands to halt uranium enrichment.
Iran's Deputy Oil Minister Mohammad Hadi Nejad-Hosseinian said today there was "some possibility" of a US attack on his country over its nuclear weapons programme.
He also warned crude oil prices could exceed $100 a barrel by winter as supplies cannot be increased in the short term.
Apart from Iran, unrest in Nigeria's has also boosted interest in the oil futures market and helped to lure investment class and hedge fund money, which has flooded in across the commodities complex.
Bolivian oil nationalisation has also stoked concern about the difficulty of accessing the world's energy reserves.
President Evo Morales ordered the military to occupy Bolivia's natural gas fields yesterday after nationalising the industry and threatening to expel foreign companies that do not recognise state control.
Saudi Arabia, the world's biggest oil exporter, said current price strength was not the result of inadequate supplies.