MUMBAI, November 7 (Reuters) - ICICI Bank Ltd, India's biggest private-sector lender by assets, reported a 2.4 percent rise in second-quarter net profit on Monday due to lower tax expenses while its provisions surged more than seven times. Standalone net profit rose to 31.02 billion rupees ($465 million) for the three months to Sept. 30 from 30.30 billion a year earlier, well above the 25.65 billion rupees average of 26 analyst estimates, according to Thomson Reuters data. Bad loans as a percentage of outstanding loans rose to 6.82 percent at the end of September from 5.87 percent at the end of June. Indian banks were saddled with $138 billion of stressed loans as of the end of June. While state-owned lenders account for bulk, ICICI has the highest proportion among private sector banks. The amount of bad loans has surged this year after an asset quality review ordered by the Reserve Bank of India uncovered more than previously calculated. The central bank has set a March 2017 deadline for the sector to fully disclose and make provisions for those. ICICI's provisions, which include charges for bad loans, jumped to 70.83 billion rupees in the September quarter from 25.15 billion rupees three months earlier and more than seven times higher than a year earlier. The bank said total provisions in the second quarter included extra provisions of 35.88 billion rupees which it took to strengthen its balance sheet. Tax expenses fell to 4.51 billion rupees in the September quarter from 11.86 billion rupees a year earlier due to deferred tax adjustments.