BEIJING, Aug. 6 (Xinhua) — China has issued a circular to promote the development of credit rating businesses in the bond market to facilitate the healthy growth of the market. Credit rating institutions should improve their rating methodology systems, said the circular jointly issued by the People’s Bank of China, the National Development and Reform Commission, the Ministry of Finance, the China Banking and Insurance Regulatory Commission, and the China Securities Regulatory Commission. The circular requires these institutions to establish and use rating methodology systems that can achieve reasonable differentiation by the end of 2022 to effectively improve the quality…