Chinese credit-rating agency Dagong Global Credit Rating Co. again downgraded U.S. sovereign debt Wednesday and warned of further downgrades, the state-run Xinhua news agency reported.... Dagong cut U.S. Treasurys to A from A+, with a negative outlook, saying growth in U.S. debt is still outpacing revenue growth. The latest move followed a Dongang downgrade of U.S. debt from AA to A+ in November, citing the launch of the Federal Reserve's second round of quantitative easing. "The agency said the approval to raise the debt ceiling indicated that there will not be any positive changes in factors that will influence the...