U.S. oil prices extended gains in Asia on Wednesday on an unexpected stockpile draw and higher gasoline prices, while international crude markets remained weak on the back of low growth expectations. The recent divergence in American and international markets has reduced the discount between U.S. and global crude benchmarks by almost two thirds during the past month to around $2.50 per barrel. U.S. crude futures rose after industry group the American Petroleum Institute (API) reported a 3.1 million-barrel crude drawdown last week, versus analyst expectations for a build.