Activity in Chinas factories expanded at the slowest pace in five months in March, a private gauge indicated, in contrast with official data showing manufacturing activity at a three-month high. The Caixin China manufacturing purchasing managers index dropped to 51.0 in March from 51.6 in February, Caixin Media Co. and research firm Markit said Monday. The 50 level separates an expansion in manufacturing activity from a contraction. New orders grew at the slowest rate in four months, due to muted foreign demand and only a slight improvement in external demand, Caixin said. Production levels rose at the slowest pace since November as a result of lukewarm demand, Caixin said.