Led by IT majors Infosys and TCS, the combined market capitalisation (m-cap) of top six Sensex companies plummeted by Rs 64,122 crore last week amid weak stock market.

The market value of Infosys sunk by Rs 25,677 crore to Rs 1,38,004 crore on Friday, when it reported fourth quarter earnings and gave muted revenue guidance for this fiscal.

Infosys shares plunged 13 per cent, wiping out nearly Rs 20,000 crore in market value in a single day, as disappointed investors resorted to hectic selling.

Analysts said the biggest disappointment was Infosys’ revenue guidance for the next year, which is taken as a benchmark for the entire IT industry.

Infosys gave lower-than-expected revenue guidance of $7,553 million-7,692 million, representing a full-year growth of 8-10 per cent. This is lower than industry body Nasscom’s estimate 11-14 per cent growth estimate for the Indian software services industry for 2012-13.

Country’s biggest IT company TCS also saw a dip of Rs 21,295 crore from its m-cap, which was Rs 2,09,334 crore. Both Infosys and TCS together added Rs 46,972 crore to the total loss suffered by the top six companies.

ONGC’s valuation declined Rs 10,738 crore to Rs 2,23,169 crore, while Bharti Airtel lost Rs 2,867 crore from its m-cap which stood at Rs 1,22,451 crore.

Market worth of Coal India Ltd slipped by Rs 2,432 crore to Rs 2,13,335 crore, while NTPC shed Rs 1,113 crore from its value which was Rs 1,37,204 crore.

In contrast, RIL, ITC, SBI and HDFC Bank saw surge in m-cap last week. RIL added Rs 1,359 crore to its m-cap which was Rs 2,46,000 crore, while ITC saw a gain of Rs 7,076 crore to Rs 1,84,671 crore.

SBI’s m-cap surged Rs 2,994 crore to Rs 1,40,426 crore, while HDFC Bank added Rs 855 crore to its value which was Rs 1,24,271 crore.

In the list of the top-10 companies, RIL held the top position, followed by ONGC. CIL toppled TCS to become the country’s third most valued company. It was followed by TCS, ITC, SBI, Infosys, NTPC, HDFC Bank and Bharti.

In terms of the weight on Sensex, Infosys slipped to third position after RIL and ITC losing its ‘most influential stock’ status.

The BSE 30-share benchmark Sensex lost 2.23 per cent to end the week at 17,094.51.