Karnataka Bank Ltd. shares plunged 6.8% on Tuesday, erasing nearly Rs 1,100 crore from the lender’s market capitalization and closing at Rs 288.20 amid a broader banking sector rout triggered by escalating concerns over asset quality deterioration, stringent regulatory interventions from the Reserve Bank of India (RBI), and a persistent slowdown in credit offtake. The Mangaluru-based private sector bank’s decline, the steepest among Nifty Midcap 100 financial services stocks,