Global oil prices drifted lower on Wednesday, mirroring losses on European stock markets, as traders awaited the weekly report on inventories in top crude consumer the United States.
Brent North Sea crude for delivery in June slid 57 cents to $99.34 per barrel approaching midday in London.
New York's main contract, West Texas Intermediate (WTI) light sweet crude for May, dipped 62 cents to $88.10
Brent had plunged on Tuesday to a nine-month low of $98 on demand fears after poor Chinese and US economic data, with sentiment also hit by the Boston Marathon bombings and ongoing tensions on the Korean peninsula, analysts said.
"Crude oil prices continued their sharp downside momentum on Wednesday with Brent oil trading below the crucial level of $100 per barrel, while WTI crude oil also remains under pressure," said Sucden analyst Myrto Sokou.
"It seems that the oil market is tracking losses in the European equity markets as market sentiment remains fairly bearish.
"The US dollar found some support, especially following better than expected US data on Tuesday, and started to strengthen against a basket of currencies, adding further pressure."
The stronger greenback makes dollar-priced crude more expensive for buyers using weaker currencies. That tends to hit oil demand and price levels.
Later on Wednesday, the US government's Energy Information Administration will publish its report on American energy reserves for the week ending April 12.
Crude stockpiles are expected to increase by 900,000 barrels, according to analysts polled by Dow Jones Newswires.