Prices have fallen by almost $10 a barrel over the last two weeks since hitting a 15-month peak of $83.95 on January 11.
Wall Street stocks capped their worst three-day slide in 10 months on Friday on fears President Barack Obamas plan to limit risk-taking by banks would undermine profits.
At the end of last week, commodities were pressured after President Obama announced plans to curb risk taking on Wall Street by limiting trading activity of financial institutions and banning commercial banks from proprietary activity, JBC Energy analyst David Wech said.
Besides raising concerns that the new ruling could threaten the profitability of the financial sector, Obamas plan also raised worries concerning liquidity in commodity markets.
US crude for March delivery declined 18 cents to $74.36 a barrel by 0950 GMT. The contract fell $1.54 to settle at $74.54 a barrel on Friday, the lowest settlement since December 22, after trading as low as $74.01. London ICE Brent rose 13 cents to $72.95.
Oil prices have broken below the 100-day moving average of $75.20, a key indicator of market sentiment. Demand for oil remains relatively weak in the wake of the financial crisis.
Analysts said sentiment during the week would be shaped by the latest US Federal Reserve comments on interest rates due on Wednesday as well as US existing home sales data and gross domestic product for the fourth quarter.
China, the fastest growing oil market and the worlds second largest energy consumer, is also in focus, with signs Beijing could move to tighten monetary policy to rein in its booming economy.
Asian and European equity markets slipped on Monday.
Having fallen in seven out of eight trading sessions since January 11, oil prices could see some trend-line support near current levels, analysts said. More bearish news could push the price toward a low of $68.59 -- last seen in late December.
Separately, Mexico closed its Dos Bocas oil terminal on Sunday due to bad weather, the government said. Almost all of Mexicos crude oil exports are shipped to refineries on the Gulf Coast of the US.
US stocks could also see choppy trading this week with the latest batch of earnings and uncertainty over Ben Bernankes Senate confirmation for another term as Federal Reserve chairman.
Money managers boosted their net long crude oil futures position on the New York Mercantile Exchange in the week through January 19, the Commodity Futures Trading Commission (CFTC) said on Friday, but some analysts cautioned this could actually lead to lower prices.