Brent crude oil edged down on Tuesday in reaction to weak manufacturing data in China and Europe, but it closed above $100 a barrel for the second straight day as it drew some support from strong gains in U.S. equity markets.
The flash HSBC Purchasing Managers' Index for April fell to 50.5 from 51.6 a month earlier as new export orders shrank in China.
(Read More: Growth Worries? Asia Should Hail That Oil Price Fall)
The PMI's 50-point level divides growth from contraction from the month before. The data followed lower-than-expected GDP growth for China in the first quarter which helped spark a sharp sell-off last week.
There was also a surprise decline in business activity among German companies, although the overall euro zone services PMI rose slightly and met economists' forecasts.
"People are worried about a slowdown in China and Europe, but I think with the stock market going higher today, Brent is going to rebound a bit," said Mark Waggoner, president at Excel Futures in Portland, Oregon.
He cited $100 as a psychological level off which Brent had been bouncing in recent days.
Brent crude futures settled down 8 cents at $100.31 a barrel, after falling by more than $1.50 in earlier trading. U.S. light, sweet crude settled down 1 cent at $89.18 a barrel after falling more than $1 in intraday trading.
Shortly after 1 p.m. EDT, a bogus post on the Associated Press Twitter account reporting two explosions in the White House sent U.S. stock, oil, and Treasury markets down sharply before bouncing back in a matter of minutes or seconds. Gold briefly surged up before trading lower.
"It puts into perspective our increasing dependence on technology and communications," said Bill Baruch, senior market strategist at iitrader.com in Chicago.
"It brings us back to reality in the sense that these communications are easily misconstrued, easily hacked, so not only can people put out false information, but they can capitalize on it."
Even after their steep drop, U.S. stock markets were all up around 1 percent on Tuesday on robust earnings across sectors, giving support to the oil markets, which often trade in tandem with equities.
"Stronger equities pulled the crude market up from its lows. Crude has become another financial instrument, driven by risk-on, risk-off trading," said Kyle Cooper, the managing director of research at IAF Advisors in Houston, Texas.
Tim Evans, an energy specialist at Citi Futures Perspectives, said that gasoline, which was off nearly 2 percent, was relatively immune to the stock market's rallies, calling it "the weakest element of the complex, with weak physical demand, rising refinery throughput and ongoing vulnerability from excess speculative length."
Brent had settled above $100 on Monday for the first time in five sessions as traders saw oil below that threshold as a bargain.
The benchmark has fallen nearly 9 percent so far this month, the biggest such fall since last June, on concerns about global growth.
In response to China's moderate growth, Saudi Arabia was expected to keep oil output steady throughout the second quarter after a 700,000 barrels per day (bpd) cut in the last two months of 2012.
Violence in oil producing countries, which raised supply worries, helped prevent a sharper drop.
At least 40 people were killed on Tuesday when Iraqi forces and Sunni Muslim protesters clashed after troops raided their anti-government demonstration camp near Kirkuk, military sources said.
Later in the day, at least seven people were killed and 17 more wounded when two roadside bombs targeted worshippers as they were leaving a Sunni Muslim mosque in southern Baghdad, police said.
A car bomb in Tripoli wounded two French guards at France's embassy in Libya on Tuesday, bringing new violence to the capital, which has not seen attacks on diplomats like that which killed the U.S. ambassador in Benghazi last year.
Fighting in Africa's top energy producer Nigeria and a force majeure on its Bonny Light crude exports also helped to put a floor under Brent prices.
Investors will watch weekly oil inventories data from the United States due on Tuesday and Wednesday to gauge demand in the world's largest oil consumer.
U.S. commercial crude oil stockpiles were forecast to have climbed by 1.5 million barrels last week on increased imports, and oil products are also seen higher, a preliminary Reuters poll of 10 analysts showed Tuesday.