Eyes are on the December 4 Opec meeting to gauge the outlook for the global glut.
"Ultimately, we still see a drop to around US$37.75, but such a development is not expected until the market gets through the Opec meeting at the end of next week and when increasingly bearish global supply balances place additional pressure on the WTI curve," Jim Ritterbuch of Chicago-based oil consultancy Ritterbusch & Associates, told Reuters.
Meanwhile, some say US equities hold relatively more appeal.
"When you see this type of uncertainty happening, it reinforces looking at the US as a safe haven," Tom Anderson, chief investment officer at Boston Private Wealth, told Bloomberg. "The US economy is in very solid shape. We're pretty positive on equities as a result. But there's certain to be noise and volatility around those events."
There was fresh evidence of the strength of the US economy, which also underpinned expectations the Federal Reserve might feel comfortable enough to raise interest rates next month, for the first time since 2009.
A Commerce Department report showed US gross domestic product increased at a 2.1 per cent annual pace in the third quarter, up from the 1.5 per cent rate estimated last month.
"This is a sturdy second GDP print for the third quarter when looking past the inventory swings," Robert Kavcic, a senior economist at BMO Capital Markets in Toronto, told Reuters. "Importantly, domestic demand in the US economy remains very solid, something that will surely give comfort to the Fed as it ponders its next move."
Separately, the S&P/Case Shiller composite index of 20 metropolitan areas jumped a larger-than-expected 5.5 per cent in September on a year-over-year basis, up from 5.1 per cent in the year to August.
In Europe, the Stoxx 600 Index finished the day with a 1.2 per cent slide from the previous close. The UK's FTSE 100 Index fell 0.5 per cent, while Germany's DAX Index sank 1.4 per cent, as did France's CAC 40 Index.