Kotak Mahindra Bank posted a 14.8 per cent rise in second-quarter net profit on Wednesday, boosted by higher interest and fee income, but missed analysts' expectations.Net profit rose to Rs 1,142 crore ($155.84 million) for the quarter ended September 30, missing analysts' average estimate of Rs 1,165 crore, according to data from Refinitiv.Asset quality was stable, with gross bad loans as a percentage of total loans standing at 2.15 per cent at end-September, compared with 2.17 per cent a quarter earlier and 2.47 per cent a year earlier.Interest earned climbed 22.1 per cent to Rs 5,811 crore, with loans as of end-September growing 21 per cent, the Mumbai-based private sector lender said in a statement.Net interest margin - the difference between interest paid and earned, a key gauge of profitability, fell to 4.2 per cent from 4.4 per cent a year earlier.At 1:45 pm, shares in Kotak Mahindra Bank were trading 1.1 per cent lower at Rs 1,161.50 apiece on the NSE, whose benchmark index Nifty was up 0.6 per cent.