Growth in China's vast manufacturing sector picked up in March after a holiday dip, a preliminary survey of factory managers showed on Thursday, pointing towards solid but not spectacular first-quarter growth in the world's second-largest economy. The HSBC Purchasing Managers' Index for March revived to 51.7 in March from 50.4 in February, but remained below a two-year high of 52.3 reached at the beginning of the year. The pullback in February had raised concerns in financial markets that China's recovery was losing steam. Indeed, official data earlier in March suggested the economy had started 2013 with only tepid growth after a burst in the fourth quarter. Economists' opinions were mixed on how much recovery momentum would be carried into the second quarter, with some pointing to weak commodity demand while others took comfort in the stronger March showing. "Current readings around the 50 points level seem to us to be consistent with GDP growth close to 8 pe