What is the main idea of the news item? [originaltext] World oil prices rose

World oil prices rose in early trading Tuesday ending a three-day slide, The price of crude oil for future delivery gained 2. 5% during trading in New York to more than $ 72 a barrel. Oil industry analysts say the increase is due to renewed interest in oil and other commodities from investors who are worried about the declining value of the U. S. dollar. The U. S. dollar lost value compared to other currencies Tuesday after Russian President Demitry Medvedcv suggested the world should lessen its dependence on the dollar, which many countries used to pay off their debts.