Infosys weighting in the BSE Sensex currently stands at 9.70 per cent, only 15 basis points away from 9.85 per cent for ITC, Thomson Reuters Data shows.
In the Nifty, Infosys' weighting stands at 8.41 per cent compared with 8.58 percent for ITC.
Software exporter Infosys shares rose 16.4 per cent in the last three months on rupee depreciation and hopes of higher business from the United States, while ITC Ltd, a bet on domestic consumption, fell 11.7 percent in the same period on valuations and a slowing economy.
Infosys overtook Reliance Industries Ltd as the stock with second-biggest weighting in the benchmark index in October.
Infosys shares were up 1.2 per cent after earlier touching a record high of 3,557.60 rupees.