Brent crude oil dropped by more than $2 to below $107 a barrel as a strong dollar outweighed previous concerns over a drop in Libyan crude exports.
Brent crude for December delivery was down by $2.14 at $106.70 after rising as high as $109.41 a barrel in early trading, Reuters reported.
U.S. oil for December was down $1.37 at $95.01, putting it in line for a fourth straight week of declines, its longest losing streak since June 2012.Global equity markets slipped on Friday despite upbeat factory data worldwide, while the euro fell to a two-week low against the dollar on expectations that a rate cut by the European Central Bank is possible by the end of the year.
The euro fell 0.74 percent to $1.3482.
The dollar was up 0.43 percent against the yen at 98.77 yen, according to Reuters data.