Most oil prices weakened on commodity markets.

Prices of crude oil and refined petroleum products weakened after posting early gains. On the New York Mercantile Exchange, March contracts for West Texas Intermediate, the benchmark grade of U.S. crude, closed at $20.17 a barrel, down from Monday’s closing price of $20.83 but still higher than Friday’s close of $19.50. A barrel is the equivalent of 42 gallons. In addition, several leading oil companies, including Texaco, Chevron and Conoco, announced a new round of cuts in the price they will pay for domestic crude oil, with the latest reductions ranging from $1.30 to $2 a barrel.