BENGALURU, May 3 (Reuters) - Indian shares fell on Monday as conglomerate Reliance Industries slid after missing quarterly profit estimates, and as investors weighed growing calls to curb economic activity to check a relentless surge in COVID-19 infections. The NSE Nifty 50 index declined 0.53% to 14,553.4 by 0508 GMT, while the benchmark S&P BSE Sensex dropped 0.66% to 48,460.4, after shedding more than 1% each in early trading. India reported more than 300,000 new coronavirus cases for a twelfth straight day, taking its overall caseload to just shy of 20 million. A leading industry body on Sunday urged authorities to take the “strongest national steps” and to curtail economic activity to save lives, while the Indian Express newspaper reported the country’s COVID-19 taskforce had advised the federal government to impose a national lockdown. “There may be a knee-jerk reaction in markets if any drastic measure is announced, but we have experienced harsh lockdowns before, so industries will be better placed and there may not be as big an impact in the medium term,” said Nirali Shah, head of equity research at Samco Securities. Prime Minister Narendra Modi’s government is reluctant to impose a national lockdown on concerns about its economic impact, although several states have announced restrictions. Reliance, the country’s largest company by market value, fell as much as 2.6% after reporting quarterly profit that missed expectations as costs climbed. The Nifty Bank index was the worst performer, dropping 2.3%, led by leading private-sector lenders HDFC Bank and ICICI Bank. Yes Bank slumped 11.7% after reporting a loss for the March quarter due to higher provisions. Larger rival IndusInd Bank advanced 3.5% after posting a jump in profit, while SBI Life Insurance, which will report its results later in the day, climbed 3%, plugging losses on the Nifty. Kotak Mahindra Bank was down 1% ahead of its results. (Reporting by Chris Thomas in Bengaluru; Editing by Vinay Dwivedi and Subhranshu Sahu) Our Standards: The Thomson Reuters Trust Principles.