The Nifty gained 19.95 points or 0.10 per cent to 20,926.35.
"The market's focus now shifts to the upcoming FOMC (Federal Open Market Committee) meeting. And the recent global upside is getting far stretched in anticipation of a rapid fall in US Fed rate in CY 2024," said Vinod Nair, Head of Research at Geojit Financial Services.
Among the Sensex firms, NTPC, Power Grid, Mahindra & Mahindra, Larsen & Toubro,
Tata Consultancy Services, Infosys, Axis Bank,
In the broader market, the BSE midcap gauge climbed 1.06 per cent and smallcap index gained 0.73 per cent.
Among the indices, services climbed 1.50 per cent, realty jumped 1.45 per cent, utilities (1.33 per cent), power (1.25 per cent), auto (1.17 per cent) and consumer discretionary (0.85 per cent).
In contrast, IT, telecommunication, bankex, oil & gas and teck were the laggards.
"Asian shares were mixed while European markets were up on Wednesday, as traders waited for the year's final policy decision from the Federal Reserve and clues on whether the central bank will cut rates next year," said Deepak Jasani, Head of Retail Research, HDFC Securities.
In Asian markets, Seoul, Shanghai and Hong Kong settled lower while Tokyo ended in the positive territory.
European markets were trading with gains. The US markets ended in positive territory on Tuesday.
"Domestic equities were lacklustre ahead US Fed's decision late today. Nifty remained in negative territory for the most part of the day but last hour buying helped indices to close in green with marginal gains of 20 points at 20,926 levels," Siddhartha Khemka, Head - Retail Research, Motilal Oswal Financial Services Ltd, said.
Global oil benchmark Brent crude declined 0.27 per cent to USD 73.04 a barrel.
Foreign institutional investors (FIIs) were buyers on Wednesday as they bought equities worth Rs 4,710.86 crore, according to exchange data.
Snapping its declining trend, retail inflation rose to a three-month high of 5.55 per cent in November on firming food prices, including vegetables and cereals, though it remains within the RBI's comfort zone of less than 6 per cent.
After a two-day rally, the BSE benchmark fell by 377.50 points or 0.54 per cent to settle at 69,551.03 on Tuesday. The Nifty declined 90.70 points or 0.43 per cent to 20,906.40.