BENGALURU, Aug 25 (Reuters) - India"s blue-chip stock index S&P BSE Sensex touched an all-time high on Wednesday, boosted by technology and metal stocks, with sentiment aided by strength in global peers as worries about the tapering of the Federal Reserve"s pandemic-era stimulus eased. By 0516 GMT, the NSE Nifty 50 index (.NSEI) was just shy of a record high, up 0.36% at 16,685.35, while the Sensex (.BSESN) was up 0.28% at 56,115.3. Both the indexes were on track for their third straight session of gains. Indian benchmark indexes have flirted with record highs in recent months on abundant liquidity and reopening of some states after coronavirus restrictions, but analysts have warned that the domestic market"s rally may not sustain. "The IT pack has helped the index maintain positivity, but broader markets are seeing some profit-taking. The move is likely to be gradual from here on and we"re going to see selective participation," said Ajit Mishra, vice president for research at Religare Broking. A Reuters poll of analysts has also showed that the country"s liquidity-driven stock market rally is expected to cool next year as global and domestic monetary policies start to tighten. read more Among individual sectors and shares, Tata Motors (TAMO.NS) jumped as much 2.8% after hitting its lowest since early-February on Tuesday. The Nifty Metal index (.NIFTYMET) rose as much as 1.6%. The IT subindex (.NIFTYIT) too climbed 1.6% on gains in Coforge (COFO.NS) and L&T Infotech (LRTI.NS), up 5.72% and 2.6%, respectively. Asian markets held onto recent gains after last week"s pummelling, as global equities rebounded due to a combination of positive COVID-19 vaccine news and easing worries over the Fed"s stimulus. Reporting by Vishwadha Chander in Bengaluru; editing by Uttaresh.V Our Standards: The Thomson Reuters Trust Principles.