Global oil prices weakened today as dealers await the outcome of a Federal Reserve meeting and the release of a US supply report, analysts said.
New York's West Texas Intermediate (WTI) for March delivery fell 72 cents to $45.51 a barrel.
European benchmark Brent North Sea crude for March declined 26 cents to stand at $49.34 a barrel in London deals compared with yesterday's close.
Crude futures had rebounded yesterday from six-year lows as the dollar weakened following disappointing US economic data.
Later tonight, the US Federal Reserve is expected to release a post-meeting statement after the first gathering this year of its policy-making Federal Open Market Committee.
Analysts said that investors would pore over the statement for clues to the Fed's thinking on the timing for an expected interest rate hike later this year, the first since 2006.
The Fed has kept its key federal funds rate pegged between zero and 0.25% since late 2008 to support the US economy's recovery from the deep 2008-09 recession.
In October, the Fed ended its massive asset-purchase programme, or quantitative easing, and has signalled that a rate hike would be coming this year.
Most analysts expect the increase will arrive by June. Interest rate adjustments are closely watched by crude investors as an increase usually leads to a pick-up in the dollar.
A stronger greenback makes dollar-priced oil more expensive for buyers using weaker currencies, denting demand.
Analysts said oil prices were also pressured after industry group the American Petroleum Institute said US crude reserves likely surged by 12.7 million barrels in the week to January 23. The US government's Department of Energy will release the official stockpiles report later today.