Investing.com - West Texas Intermediate oil futures fell further below the $50-a-barrel level on Tuesday, as lingering concerns over a glut in global supplies continued to weigh.
On the New York Mercantile Exchange, crude oil for delivery in February lost 78 cents, or 1.56%, to trade at $49.26 a barrel during European morning hours, after falling to a session low of $49.25, the weakest level since April 2009.
Nymex oil futures plunged $2.65, or 5.03%, on Monday to settle at $50.04 a barrel.
Elsewhere, on the ICE Futures Exchange in London, Brent oil for February delivery hit a low as $52.06 a barrel, a level not seen since April 2009, before trading at $52.09, down $1.02, or 1.92%.
A day earlier, London-traded Brent prices tumbled $3.31, or 5.87%, to close at $53.11.
The US dollar index, which measures the greenback against a basket of six major currencies, traded near a nine-year high, boosted by the diverging policy outlook between the Federal Reserve and central banks in Europe and Japan.
Oil prices typically weaken when the U.S. currency strengthens as the dollar-priced commodity becomes more expensive for holders of other currencies.
London-traded Brent prices lost nearly 48% in 2014, while WTI futures dropped almost 46% after the Organization of Petroleum Exporting Countries decided to maintain its output target at 30 million barrels a day.
The decision disappointed hopes the oil cartel would lower production to support the market, as a surplus develops amid the shale boom in the U.S., which is pumping at the fastest pace in more than 30 years.