PetroChina, the country’s top gas producer, has curbed supplies of the fuel to some industrial users in northern and western regions, in the first sign of emerging tightness only two months after China experienced one of its worst winter gas crunches.  To prevent another around of winter shortages, state-run PetroChina started from early May limiting gas supplies and hiking prices for major customers, including city gas distributors and inland gas liquefaction plants in some western provinces, four sources briefed on the matter said. They declined to be identified as they are not authorized to speak to the media. “Suppliers are managing the increases in demand, so that they won’t be caught up in a serious supply crunch later in the year,” said Chen Zhu, managing director of […]