China’s factory activity sputtered in December, underlining the challenges facing the country’s manufacturers as they fight rising costs and softening demand in a cooling economy. After a rough 2014, the world’s second-largest economy looks set to start the new year on a weak note, reinforcing expectations that Beijing will roll out more stimulus to avert a sharper slowdown which could trigger job losses and debt defaults. A property slump is expected to last well into 2015, companies will continue to struggle to pay off debt and export demand may remain erratic, leaving only the services sector as the lone bright spot in the economy. China’s official Purchasing Managers’ Index (PMI) slipped to 50.1 in December from November’s 50.3, a government study showed on Thursday, its lowest level of the year and clinging just above the 50-point level that separates growth from contraction on a monthly basis. […]