(Adds details, analyst comments, updates shares) BENGALURU, Oct 28 (Reuters) - Indian shares fell on Thursday, dragged down by metals stocks on the back of sharp declines in global prices, while Adani Ports slumped 7% after saying it would exit its Myanmar investment. The blue-chip NSE Nifty 50 index and the benchmark S&P BSE Sensex fell 1% each to 18,017.50 and 60,538.57, respectively, by 0538 GMT. Copper and aluminium prices hit multi-month lows on easing supply concerns, pulling down the Nifty metals index 3.2%. “Chip shortage and supply chain issues are impacting the manufacturing sector, which has led to lower demand for metals. Also, there is a slowdown in Chinese real estate markets. Both of these macro factors are weighing on metal stocks,” said Saurabh Jain, assistant vice president at SMC Securities in New Delhi. “There is some exuberance in terms of valuations in certain pockets of the market. In some pockets, there is still money to be made, which will see some sectoral churn.” India’s benchmark stock indexes have risen more than 25% this year, driven by massive liquidity and huge retail participation, raising concerns of overvaluations. Adani Ports is abandoning its plans to build a container terminal in Myanmar, weeks after applying for a U.S. licence for the project, saying it believed it did not violate sanctions. Shares of IndusInd Bank rose 6.4% on strong September-quarter profit and improving growth prospects. The Nifty bank index and the public sector bank index were among the top drags, falling 1.8% and 3.7%, respectively. Meanwhile, digital payments leader Paytm boosted the size of its initial public offering to 183 billion rupees ($2.44 billion) from 166 billion rupees, as existing shareholders look to sell more stake ahead of the country’s largest stock market listing. Reporting by Nallur Sethuraman in Bengaluru; Editing by Anil D’Silva and Subhranshu Sahu