(EnergyAsia, May 19 2011, Wednesday) — Rotary Engineering Limited, a Singapore-listed provider of engineering, procurement, construction and maintenance (EPCM) services to the oil, gas and petrochemical industries, has posted a 62% drop in net profit to S$5.3 million for the first quarter of 2011. Its revenue was down 27% to S$130.5 million. (US$1=S$1.25).Rotary said it…