Mumbai, Aug 27 (IANS): Premium valuations, along with global cues, especially from the US Fed's symposium, subdued key domestic indices on Thursday.

Indices erased their initial gains to end on a flat note.

Globally, investors waited for more clarity on monetary policy from US Fed's ongoing Jackson Hole Symposium, while triggers in Asia, specifically from China, subdued indices.

On the domestic front, volumes were once again below recent averages.

Sector-wise, metals and telecom stocks came under pressure whereas oil and gas, power and capital goods stocks gained.

The S&P BSE Sensex fell to 55,949.10, up by 4.89 points, or 0.0087 per cent, from its previous close.

The NSE Nifty50 closed a bit higher. It rose to 16,636.90, up by just 2.25 points, or 0.014 per cent, from its previous close.

"Nifty has once again started to form flat closes day after day, like it did in Aug 05-11 period. However post Aug 11, the Nifty broke upwards of the range," HDFC Securities' Head of Retail Research, Deepak Jasani said.

"As long as Nifty is not able to post healthy day on day gain, the broader market will struggle to bounce up."

Motilal Oswal Financial Services' Head, Retail Research, Siddhartha Khemka said: "After sharp outperformance in the past 18 months led to concerns on valuation front and the likely impact on liquidity due to changes in global monetary policy had investors concerned over the last few days."

"Hence, we had seen market interest shifting away from mid-caps to large caps."