Crude prices rallied more than 4% Tuesday, as sharp weakness in the U.S. dollar boosted commodities, and as energy traders looked ahead to the upcoming meeting of the OPEC oil cartel. The gains came as the U.S dollar slumped to its lowest level in almost a year against a basket of currencies and gold rallied above $1,000 an ounce, its highest since March 2008.

The Organization of Petroleum Exporting Countries, which accounts for about one-third of the world's oil production, is scheduled to meet Wednesday in Vienna. Analysts expect the cartel to keep its production quota unchanged while pressuring member countries to comply with their current production limits.

Oil prices, which fell 6.5% last week, have been trading in a range between $65 and $75 a barrel since the start of August, with prices swinging on economic data as investors seek clues about the speed of a recovery from the recession. Investors will be on watch for inventory data, delayed by a day this week due to Monday's holiday. The U.S. Energy Information Administration report will be issued Thursday at 15:00 GMT.