Indian markets open firm; sugar stocks surge on ethanol push

Nifty opened firm on expiry day, trading above 24,700, with Reliance and energy stocks lifting sentiment. Sugar shares rallied 5-12% after government removed curbs on ethanol production from cane juice, syrup and molasses. CEAT gained on Michelin deal, Puravankara on Mumbai project rights. Analysts see expiry range-bound between 24,550-24,750, with key support at 24,490 and resistance near 24,820.