The yuan hit a record post-revaluation high in exchange-based trade Thursday, closing at 7.7935 to the dollar after the central bank set the parity rate at 7.7977 yuan to the dollar, AFP reported. The yuan closed Wednesday at 7.8081 to the dollar. Dealers attributed the appreciation to some US dollar weakness and China's galloping economic growth that has ramped up exports of everything from cheap plastics to more sophisticated electronics. The breakthrough came the day day after Beijing announced a 74% surge in the trade surplus for 2006 to a record US$177.47 billion. In Hong Kong, the value of the yuan marched past the Hong Kong dollar for the first time in 13 years, hitting 0.99966 yuan as officials there applauded the decision announced Wednesday to allow mainland financial institutions to issue yuan-denominated bonds in Hong Kong.