BEIJING, June 27 (Reuters) - Profits at China’s industrial firms rose 36.4% in May from a year earlier to 829.92 billion yuan ($128.58 billion) official data showed on Sunday. That was a slowdown from the 57% surge reported in April, according to National Bureau of Statistics. The industrial profit data covers large firms with annual revenue of over 20 million yuan from their main operations. For the January-May period, industrial firms’ profits grew 83.4% from the same period a year earlier to 3.42 trillion yuan ($1 = 6.4545 Chinese yuan renminbi) (Reporting by Gabriel Crossley; Editing by Kim Coghill and William Mallard) Our Standards: The Thomson Reuters Trust Principles.