Nigeria Turmoil Spurs Crude

Crude futures strengthened Friday on the New York Mercantile Exchange as renewed violence in Nigeria threatened to affect oil production and exports there.

Oil advanced 92 cents to $72.55 a barrel. Reformulated gasoline gained 3 cents to $2.30 a gallon, and heating oil edged 3 cents higher to $2.10 a gallon.

Natural gas fell 9 cents to $6.49 per million British thermal units.

After a period of relative calm, violence is rearing its head in the Nigerian delta region again. The rebel group MEND announced the end of a month-long cease fire, and Thursday a criminal group kidnapped the 3-year-old daughter of a British expatriate and demanded that a ransom be paid for her release.

"Whenever there is heightened risk of terrorism or other geopolitical risks, traders don't want to hold a short position going into a weekend," said Brandon DiTullio, commodities broker at Nextsource Trading. "However, the recent climb above $70 has been largely technical, and we believe that oil prices should retreat sometime soon."

Elsewhere, the U.S. Energy Information Administration announced that natural gas inventories grew by 78 billion cubic feet during the week ended June 29. A streak of temperate weather across much of the U.S. has hammered demand for natural gas, allowing inventories to grow well above the average range for this time of year.