(EnergyAsia, May 29, Thursday) — Thai Oil, Thailand’s largest refiner, suffered a 35% drop in first-quarter profit, pulled down by its petrochemicals business and lower refining margins at its 275,000 b/d plant. First-quarter profit was 3.87 billion baht, down from 5.9 billion baht in the 2007 first quarter (US$1 = Baht31.14). A shutdown at its…