Brent rose past $114 a barrel on worries about exports from Iraq, while U.S. crude dipped as data showeddh smaller draw in domestic stocks.
The U.S. dollar held onto modest gains, having risen broadly after U.S. consumer prices recorded their largest increase in more than a year in May.
Asian stocks were mixed on Tuesday with risk appetite dealt a triple blow over developments in Iraq, Ukraine and Argentina.
Asian stock markets were mixed on Wednesday as investors looked ahead to the Federal Reserve's policy decision.
Stocks climbed on Wednesday after the Federal Reserve continued to taper, and said the economy is rebounding.
Crude climbed to a nine-month high on Friday, as supply disruption fears took center stage.
Stocks fluctuated on Tuesday a day before the Federal Reserve's policy decision.
Treasury prices fell after consumer prices recorded their largest increase in more than a year, which may prompt the Fed to adopt a hawkish tone.
European shares closed higher on Tuesday, bouncing back from Monday's losses.
Gold settled lower, backing away from the previous session's three-week highs as a stronger dollar quelled appetite for safe-haven assets.
Gold was below a three-week high on Tuesday as Iraq tensions attracted some safe-haven bids, while investors waited for a Fed meeting this week.
Brent held steady above $113 per barrel while U.S. crude weakened slightly, as speculation about Iran and the West offset fears about Iraq.
U.S. stock index futures pointed to a flat-to-lower open on Wednesday, as investors awaited this month's policy decision from the Fed.
U.S. stock index futures were higher on Tuesday, as European markets shook off fears over developments in Iraq, Ukraine and Argentina.
Most U.S. Treasury prices were flat after solid economic data overcame earlier strength, as fighting overseas boosted demand for safe-haven bonds.
European shares closed lower on Monday amid concerns of escalating tensions in Iraq and rising oil prices.
The dollar was up around a third of a percent against the yen as markets listened to the Bank of Japan's latest comments on policy on Friday.
Crude pushed higher in choppy trading as advances by Sunni insurgents in Iraq fueled concerns over a potential disruption to oil exports.
The Australian dollar fell more than half a percent against the U.S. dollar on Tuesday after the RBA expressed economic recovery doubts.
Asian equities finished a choppy session mixed on Monday with escalating violence in Iraq weighing on sentiment.
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Asian markets will digest the reserve requirement ratio cut from China's central bank, while Greece remains in the spotlight.
As many as 700 people were feared dead after a fishing boat packed with migrants capsized off the Libyan coast overnight, officials said on Sunday.
China's central bank cut the reserve requirement ratio for all banks by 100 basis points on Sunday, the second reduction in two months.