Benchmark oil for July delivery was down 60 cents to $93.55 per barrel at midday Bangkok time in electronic trading on the New York Mercantile Exchange. The contract fell 10 cents to close at $94.15 per barrel on the Nymex on Friday. Monday was a public holiday in the U.S. and Britain.
Traders think global energy demand could weaken after a survey by HSBC Corp. released last week showed a decline in China's manufacturing for May. An official report on factory production in the world's second-largest economy will be released later in the week.
Data releases later Tuesday in Washington, including indexes of home prices and consumer confidence, should help clarify the state of the recovery in the world's biggest economy. First-quarter U.S. growth figures will be issued Thursday.
The dollar, posting recent gains against the yen and the euro, has also weighed on crude prices. Oil typically falls as the dollar strengthens since crude becomes more expensive for investors with other currencies.
Brent crude, a benchmark for many international oil varieties, fell 11 cents to $102.51 a barrel.
In other energy futures trading on Nymex:
— Wholesale gasoline lost 1 cent to $2.818 a gallon.
— Heating oil rose 0.3 cent to $2.857 per gallon.
— Natural gas added 3.6 cents to $4.273 per 1,000 cubic feet.