BEIJING/HONG KONG (Reuters) - China's competition watchdog is adding staff and other resources as it ramps up efforts to crack down on anti-competitive behaviour, especially among the country's powerful companies, people with knowledge of the matter told Reuters. Beijing's plan to bulk up the State Administration for Market Regulation (SAMR) comes as China revamps its competition law with proposed amendments including a sharp increase in fines and expanded criteria for judging a company's control of a market. On Saturday, the watchdog slapped a record $2.75 billion fine on Alibaba after an antimonopoly probe found the e-commerce giant had abused its dominant market position for several years.