According to a senior central bank official in an interview. China has moved ahead of Japan to become the world's second-largest economy.

Yi Gang, a vice-governor of the People's Bank of China and also the head of the State Administration of Foreign Exchange (SAFE), did not explain how he had arrived at the figures, according to the comments posted on the SAFE website.

China economy grew 10.3 percent in the second quarter and 11.1 percent in the first half.

China's gross domestic product in the first six moths stood at 17.284 trillion yuan, according to the National Bureau of Statistics. That comes to 2.5324 trillion dollars, using the central bank's average monthly exchange rates....