Billionaire Mukesh Ambani-led Reliance Industries Ltd has lost its position as the Indian stock market's most influential individual company to IT major Infosys, following a recent plunge in its share price.

Measured in terms of its weightage on the key barometer index of Indian stock market, the Sensex, RIL had been enjoying its position as the most influential stock for many years and the movement in its share price has been crucial for any major fall or rise in this index.

However, RIL has now slipped to second position after Infosys in terms of its Sensex weightage, which is measured by the market value of a company's free-float or non-promoter shares that can be freely traded in the market.

At the end of yesterday's trade, Infosys was the top- weight Sensex stock with a weightage of 10.25 per cent, pushing RIL to second slot with a weightage of 10.08 per cent.

Similarly at the NSE's Nifty index, another barometer of Indian stock market, Infosys was the top-ranked stock with a weightage of 9.13 per cent, followed by RIL's 8.48 per cent.

The weightage of a stock on these two indices changes daily as per the change in the market value of their shares.

According to market analysts, Reliance's replacement has not come as a surprise, the stock has been under-performing the market barometer Sensex for quite sometime.

On a group-basis, RIL had slipped to third slot in June this year, in terms of a corporate group's influence in moving the stock market benchmark Sensex, after HDFC and Tata groups.

HDFC Ltd and HDFC Bank together carry a weightage of over 13 per cent in the Sensex, while four Tata group firms on the index (TCS, Tata Steel, Tata Motors and Tata Power) command a weightage of close to 11 per cent.

RIL stock has crashed by 31 per cent so far this year, while Infosys' loss has been smaller at 21 per cent in this period. Also, the decline in Infosys has been slightly lower than that of 23 per cent drop in the Sensex so far this year.

As a result, RIL's free-float market value, or the value of RIL shares held by public shareholders, stood at Rs 131,091 crore, which was lower than that of Infosys at Rs 133,305 crore as on yesterday.

However, RIL remains bigger than Infosys in terms of the overall market value, including the promoter shares.

RIL's total market value stood at Rs 238,347.37 crore as on yesterday, as against Infosys' 156,829.22 crore.

RIL is the country's most valued firm, followed by TCS, ONGC, Coal India and Infosys in the top-five.

Interestingly, another IT giant Wipro, which once occupied the position of the country's most valued company, also moved back into the top-ten league today.

Wipro commanded a market cap of Rs 1,02,343 crore in the mid-day trade today at the BSE.

At the end of today's trading session also, Infosys retained its lead over Reliance Industries with a higher weigthage in the Sensex and Nifty.

Infosys commanded a weightage of 10.25 per cent on the Sensex, as against RIL's 10.20 per cent at the close of today's market hours.

On the Nifty index also, Infosys' weightage stood at 9.1 per cent, higher than RIL's 8.59 per cent.

After the close of today's trading, the free-float market capitalisation of Infosys was Rs 134,446.92 crore, slightly higher than RIL's 133,738.45 crore, as per the BSE data.

In terms of total market value, RIL retained the top slot, followed by TCS, ONGC, Coal India, Infosys, ITC, NTPC, Bharti Airtel, SBI and HDFC Bank.

Wipro slipped out of the top-ten by the end of the trading session after a brief stay at the tenth position earlier during the day.