SHANGHAI, April 12 (Reuters) - China shares dropped on Monday, weighed down by materials and transport stocks, as worries over policy tightening persisted on expectations of upbeat economic data due later this month. ** The blue-chip CSI300 index fell 1.7%, to 4,947.75, while the Shanghai Composite index shed 1.1% to 3,412.95. ** Leading the declines, the CSI300 materials index and the CSI300 transport index slumped 3.9% and 4.1%, respectively. ** Courier giant S.F. Holding Co Ltd fell 9.4%, following a 10% drop on Friday after flagging losses for the first quarter. ** China’s first quarter economic growth data probably would beat market expectations, which could raise worries over a quick tightening of monetary policy, Huaan Securities said in a report. ** The market could also encounter challenges as much stronger-than-expected PPI could lead to marginal changes in monetary policy, the brokerage added. ** Ongoing Sino-U.S. tensions also affected sentiment. ** U.S. Secretary of State Antony Blinken said on Sunday the United States is concerned about China’s aggressive actions against Taiwan and warned it would be a “serious mistake” for anyone to try to change the status quo in the Western Pacific by force. ** Foreign investors on Monday purchased a net 6.4 billion yuan ($976.71 million) worth of A-shares as they hunted for bargains, according to Refinitiv data. ** Around the region, MSCI’s Asia ex-Japan stock index was weaker by 1.14%, while Japan’s Nikkei index closed down 0.77%. ** At 07:06 GMT, the yuan was quoted at 6.5534 per U.S. dollar, 0.01% weaker than the previous close of 6.553. ** As of 07:07 GMT, China’s A-shares were trading at a premium of 33.69% over the Hong Kong-listed H-shares. ($1 = 6.5526 Chinese yuan renminbi) (Reporting by Shanghai Newsroom; Editing by Shounak Dasgupta)