China's manufacturing sector expanded in March for a fourth straight month as output and new orders continued to grow, but rising price pressures sharply intensified, a private-sector survey showed on Wednesday. The RatingDog China General Manufacturing Purchasing Managers' Index (PMI), compiled by S&P Global, fell to 50.8 in March from 52.1 in February, missing analysts' forecast of 51.6. The 50-mark separates growth from contraction. An official survey showed on Tuesday that factory activity grew at the fastest pace in a year in March, underpinned by improved demand.