Crude oil futures prices finished slightly higher Friday, after signs of progress in Europe's debt crisis vaulted markets into positive territory late in the day.

The higher close capped a day of volatile trading. Oil prices spent much of the day in negative territory, gripped by fears about the weak global recovery, but an afternoon rally in the equities market was enough to power crude futures to a positive finish.

Some market participants said it was among the most turbulent trading days in recent memory.

"It's been very brutal," said Tony Rosado, broker at GA Global Markets in New York. "You have to have extremely deep pockets to trade this market."

Light, sweet crude for September delivery settled up 25 cents, or 0.3%, to $86.88 a barrel on the New York Mercantile Exchange. The contract sank to an intraday low of $82.87 a barrel, its lowest since Nov. 26, before ending the day higher.

Brent crude on the ICE futures exchange recently traded up $2.21, or 2.1%, to $109.46 a barrel.

Futures entered positive territory late in the day after reports that Italy planned to push through labor reforms and introduce a balanced-budget amendment to its constitution as part of an agreement with European Union authorities. Investors welcomed the news as a sign that the currency bloc was making progress toward resolving its sovereign-debt crisis, sending stock markets higher and lifting oil and other commodities.

Crude futures started the day higher after the Labor Department said the U.S. economy added more jobs than expected last month. Nymex crude shot to an intraday high of $88.32 a barrel. But the rally lost steam as stock markets gave back their morning gains.

The Labor Department said nonfarm payrolls rose 117,000 last month, while the unemployment rate fell to 9.1% from 9.2%. Economists surveyed by Dow Jones Newswires had expected payrolls to rise 75,000 and the jobless rate to remain unchanged.

Oil market participants took cues from equity markets Friday, saying they've become a proxy for sentiment about the health of the global economic recovery, which correlates closely with demand for oil and gasoline.

"The price of oil seems to be going with the overall consensus of the economy, and what's the best reflection of that? The equity markets," said Peter Donovan, vice president at oil options brokerage Vantage Trading in New York.

Despite the better-than-expected jobs reading, oil market participants remained concerned that the economic recovery in the U.S., the world's biggest crude consumer, is still weak. Some 14 million Americans are still without employment, according to the Labor Department. More worrisome to crude-market watchers are signs that gasoline demand, which typically peaks in the summer, is slowing.

Nymex crude futures fell 9.2% this week, wiping out all of the year's previous gains. The recent declines could mean crude futures have found a new trading range between $80 and $90 a barrel, after rising as high as almost $115 a barrel earlier this year, analysts said.

"This week was the market's moment of clarity," said Peter Beutel, head of the oil trading advisory firm Cameron Hanover. "It suddenly saw itself staring at an economic recovery that lost its wind behind its sails."

Separately, a fire at a refinery owned by Valero Corp. (VLO) lent support to gasoline futures. The company said the fire at its 195,000-barrel-a-day facility in Memphis, Tenn., forced the shutdown of two of its crude distillation units.

Front-month September reformulated gasoline blendstock, or RBOB, settled up 6.80 cents, or 2.5%, to $2.8052 a gallon.

September heating oil settled up 4.78 cents, or 1.7$, to $2.9417 a gallon.