http://articles.marketwatch.com/201...swoman-andrea-saul-obama-campaign-mitt-romney LOS ANGELES (MarketWatch) -- U.S. President Barack Obama's campaign criticized opponent Mitt Romney on Monday for an investment in Chinese energy major Cnooc Ltd. (HK:883)(US:CEO), saying the investing position contrasted with the Republican ex-governor's stance on China. The Cnooc investment, made by Romney's blind trust and since unwound, was revealed when Romney made public his 2011 tax return late last week, the Financial Times and website BuzzFeed reported separately. "It wasn't until Romney decided that he was going to start talking tough on China ... that he dumped the shares," the Obama campaign said. The remarks came as Romney spokeswoman Andrea Saul was quoted by Reuters on Monday as saying Obama should label China as a currency manipulator, an action Romney has promised to do immediately if he wins the presidency. Romney's campaign has previously accused the White House of being soft on China.