Oil prices edged down but held near $62 on Friday as refinery glitches and lower gasoline stock levels in the United States led to worries over summer fuel demand. US crude slipped 25 cents to $61.75 a barrel, after ending 21 cents higher on Thursday at $62, its highest settlement since December 22.
London Brent crude traded 18 cents lower at $61.93. Traders said Valero Energy Corp had reduced runs at its Port Arthur, Texas, plant, adding to a string of North American refinery problems creating concerns over fuel supplies as companies' gear up for peak northern summer driving demand.
"Oil prices are benefiting from the strength of demand for petroleum products in the US," said David Moore, commodity strategist at Commonwealth Bank of Australia. Prices have been boosted this week after US data on Wednesday that showed unexpectedly large draws in inventories of distillates, including heating oil, which fell 3.8 million barrels, while gasoline slid 1.9 million barrels.
The stock data helped push the price of gasoline to a six-month high. Longer-dated oil futures have also rallied, with December 2012 up 1.7 percent this week to near $67 a barrel and outstripping the front month contract's 1.0 percent gain.
Supplies of crude from Opec producers, excluding Iraq and Angola, fell further in February, a Reuters survey showed, putting output from the 10 members bound by targets at 26.63 million barrels per day, down 290,000 bpd from January.
That is more than the 25.8 million bpd the group aimed to pump from February 1, but the drop in supply from Opec source of a third of the world's crude has helped boost prices from a 20-month low of $49.90 in mid-January.
Opec member Iran's dispute with the West over its nuclear programme has also been a supportive factor, as world powers made progress towards agreeing on new sanctions for Tehran. Analysts said oil and other commodities could continue to be influenced by volatile stock markets. US stocks slipped on Thursday, following other global stock markets lower after investors sought safety in government debt and unwound risky investments funded with the yen's rock-bottom interest rates.