China’s official Purchasing Managers’ Index, a survey of the country’s manufacturing activity, rose slightly to 50.5 in January, the highest level since October, state media reported. That measure, published by the China Federation of Logistics and Purchasing, was up from 50.3 in December, 49.0 in November and 50.4 in October, suggesting that manufacturing activity has yet to slow significantly in the world’s second-largest economy. A reading above 50 indicates expanding production, while one below 50 indicates contraction. The CLFP’s sub-index for new orders reach 50.4 in January, up 0.6 points from December as the week-long Spring Festival holiday helped to boost activity. At a news briefing on Tuesday, the CFLP said it plans to expand its PMI survey from 820 companies in 20 industries to around 3,000 companies, though it did not give a timetable for the changes.