World oil prices shed more than $1 on the back of high crude inventories and lingering concerns about weak energy demand.
US crude for January delivery, sank $1.06 to $76.40 a barrel.
Brent crude for January delivery dipped $1.58 to $75.98.
Oil prices have slumped from record highs of above $147 reached in July 2008 to about $32 in December last year, as the economic downturn hit world demand for energy.
Crude futures have slowly won back ground as major industrialised nations emerge from recession but oil demand remains weak despite reportedly rising for the first time in seven quarters.
World oil demand rose between July and September after falling during the previous six quarters, the Centre for Global Energy Studies said in a monthly report published on Monday.
The London-based CGES added that global oil demand was set to record its first year-on-year gain during the fourth quarter, although crude oil prices should continue to trade between $70 and $80 a barrel.
Crude futures were likely to stay under $80 dollars also because of high oil inventories in the US, the world's biggest energy-consuming nation, according to analysts.
New York crude prices last Wednesday breached $80 a barrel after government data showed crude reserves in the United States fell 900,000 barrels in the week ending November 13.
However levels remain relatively high with demand struggling to recover following the financial crisis.
OPEC president Jose Maria Botelho de Vasconcelos has signalled that $75-80 dollar oil is an adequate level to allow for a global economic recovery.
