US President Donald Trump threatened to raise tariffs on Chinese goods if the two economies do not sign the deal.
The Sensex was up 178 points at 40,648, while the Nifty traded higher by 47 points at 11,986.
Sectorally, the trend was mixed with Nifty Pharma leading the gainers. Nifty FMCG was the biggest loser among sectors, down 0.5%.
Top gainers included Reliance Industries, IndusInd Bank, and Sun Pharma, while losers included Britannia, ITC, and Axis Bank.
Shares of RIL rose 3.35% after its infocomm arm Jio announced its plan to hike tariffs, following peers Bharti Airtel and Vodafone Idea on Tuesday.
Shares of Vodafone Idea continued extending massive gains, up in early trade by 26%.
Meanwhile, the rupee opened lower at 71.83/$ on Wednesday amid weak global cues. The US FOMC is expected to release its minutes of the October meet later today.