HDFC Group has become India's second biggest corporate house after Tatas in terms of private sector stock market valuation, pushing energy-to-retail conglomerate Reliance Industries group to the third position.

The financial services giant HDFC Group now commands a total market value of Rs 2.41 trillion -- the second highest among all the private sector corporate houses after salt-to- software conglomerate Tatas' Rs 4.42 trillion.

In comparison, the market value of Reliance Industries group currently stands at about Rs 2.36 trillion.

The valuation of these groups have been derived after taking into account market values of all their listed companies.

While Tatas have nearly 30 listed entities, RIL group has got two (Reliance Industries Ltd and Reliance Industrial Infrastructure Ltd) and HDFC group has three -- HDFC Ltd, HDFC Bank Ltd and Gruh Finance Ltd.

HDFC group has managed to replace RIL group as the second most valued group due to a surge in the share prices of its two key companies, HDFC Bank and HDFC Ltd, in the recent past. In comparison, RIL shares have been under pressure.

In the past one month, HDFC Bank has gained nearly 7 per cent of value, while that of HDFC Ltd has also grown by about three per cent. On the other hand, RIL's valuation has fallen marginally in this time period.

Tata group's most valued company TCS has gained value in the past few days, but its share price is almost unchanged one a one-month basis.

The other major companies from the group include Tata Motors, Tata Steel and Tata Power. All these four Tata group firms are part of the market barometer Sensex.

On the Sensex, HDFC group enjoys the highest weightage, followed by Tatas at the second, ITC at the third, RIL at the fourth and Infosys at fifth.

The combined weigthage of two HDFC group stocks on the Sensex (HDFC Ltd and HDFC Bank) is 14.45 per cent currently, followed by Tatas (four stocks) with 11.19 per cent, ITC's 9.52 per cent, RIL's 8.87 per cent and Infosys' 7.45 per cent.

The Sensex weigthage determines the impact of a stock on the overall movement of the benchmark index and is determined by the company's non-promoter shareholding market value.

Incidentally, both Tatas and RIL group have lost value in the past one year, while that of HDFC group has increased.

Tata group's overall market value has fallen by about Rs 5,000 crore in the past one year, while the loss has been much larger at about Rs 47,000 crore for RIL group.

In comparison, the HDFC Group has gained more than Rs 20,000 crore in market value in the past one year.

Among the top-10 private sector corporate houses, Tatas, HDFC group and RIL group are followed by ITC (Rs 1.98 trillion), Anil Agarwal-led Vedanta group (Rs 1.63 trillion), Infosys (Rs 1.28 trillion), Aditya Birla group (1.27 trillion), Bharti group (1.17 trillion), ICICI (1.07 trillion) and Hindustan Unilever (Rs 95,000 crore).

Out of these, ITC, Aditya Birla group and HUL have also seen their market value grow in the past one year, while those like Infosys, ICICI and Bharti groups have seen erosion in their respective market valuations in this period. The overall value of Vedanta group has also grown because of addition of Cairn India through an acquisition.

Infosys has lost more than Rs 40,000 crore, while the market value of Bharti and ICICI groups have dropped by about Rs 29,000 crore and Rs 20,500 crore respectively.

On the other hand, ITC has gained over Rs 42,000 crore, while the gains for HUL, Vedanta and Aditya Birla groups are about 22,500 crore, Rs 21,500 crore and Rs 9,500 crore respectively.

Together, the top-ten corporate houses have seen their collective market value decline by about Rs 26,000 crore to close to Rs 18.6 trillion (USD 336 billion).

On individual company basis, TCS is currently the country's most valued company, followed by RIL, ITC Ltd, HDFC Bank, Infosys, Bharti Airtel, ICICI Bank, HDFC Ltd, HUL and Wipro in the top-ten among the private sector players.

Including the public sector entities as well, TCS tops the top-ten chart, followed by ONGC, RIL, Coal India, ITC, SBI, HDFC Bank, NTPC, Infosys and Bharti Airtel.