Crude oil future touched the psychological mark of 100 dollars a barrel on Wednesday on apprehensions that inventories might have fallen in the US and that trouble in Nigeria, Africa's biggest producer, will lead to cutting off or disruption in the supplies.
Crude for February delivery went up by USD 4.02 to 100 dollars a barrel on the New York Mercantile Exchange in early afternoon trading.
Violence in Nigeria gave the latest push to the prices. Groups of armed men yesterday attacked Port Harcourt, the centre of Nigeria's oil industry and raided two police stations and the lobby of a major hotel.
Word that several Mexican oil export ports were closed due to rough weather added to the gains, as did a report that OPEC may not be able to meet its share of global oil demand by 2024.
An official report due on Thursday was expected to show that crude oil inventories in the United States, the world's top energy consumer, have fallen for a seventh week in a row.
Falling inventories amid the northern hemisphere winter when demand for heating fuel is high is helping to lift the prices.