Nifty breaks below 23,000, Sensex tumbles 665 points as oil climbs, expiry volatility looms

Mumbai, Sept. 28 -- Indian equity benchmarks opened lower on Monday, with the Nifty 50 slipping below the crucial 23,000 level as rising crude prices, pressure on the rupee and higher global bond yields weighed on sentiment.The market is also heading into the month-end expiry of the Nifty and Bank…