World oil prices strengthened after a meeting between officials of Venezuela, Saudi Arabia and Mexico said the Organisation of Petroleum Exporting Countries would not alter the production limits that have helped crude double in value this year.
The market had feared that the next OPEC meeting later this month might decide that output restrictions could be eased.
In late trading yesterday on London's International Petroleum Exchange, benchmark October Brent blend was $21.04 a barrel, up 24 cents. On the New York Mercantile Exchange, October light crude was up 15 cents at $21.64 in the afternoon.
Meanwhile, nickel rose to its highest price for almost two years on the London Metal Exchange, buoyed by fears of delays in supplies from Russia owing to bad weather on Arctic export routes.
The three-month contract ended the week at $7,070 a tonne, while LME copper finished at $1,757 a tonne.
US markets will be closed on Monday for the Labor Day holiday.