Most of the Adani Group companies fell in the morning trade on Friday and flagship Adani Enterprises tumbled 10 per cent after index provider MSCI decided to reduce the weightage of four firms in its indices following a review.

Amid volatile trading in the market, seven Adani Group firms were in the negative territory while three others were in the green.

Adani Enterprises plunged 10 per cent to Rs 1,734.60 per share, its lower price band on the BSE, and the company's market valuation dropped to Rs 2.14 lakh crore.

In the morning session, Adani Power fell 5 per cent to Rs 164.30 and touched its lower price band. Similarly, Adani Transmission dropped to Rs 1,186.15, Adani Green Energy to Rs 723.90 and Adani Total Gas to Rs 1,258.25. All these scrips declined 5 per cent each.

The scrip of NDTV declined 2.56 per cent to Rs 211 and ACC fell 0.84 per cent to Rs 1,900.35 on the bourse.

However, three other Adani group firms were trading in the green territory. Adani Ports and Special Economic Zone soared 1.98 per cent to Rs 593.60, Ambuja Cements jumped 1.09 per cent to Rs 361.90 and Adani Wilmar gained 1.10 per cent to Rs 445.15.

Deepak Jasani, Head of Retail Research at HDFC securities, said MSCI Inc has cut its determined free float for four companies in the Adani Group -- Adani Enterprises, Adani Total Gas, Adani Transmission and ACC.

"Free float measures for four other companies in the group remained the same. The cuts, which will come into force at the end of February, will result in smaller weightings for those stocks in MSCI's closely watched indices, triggering outflows as investors who track the benchmarks reduce their shareholdings," he said.

Citing brokerage reports, Jasani said that given the reduction in weightage, Adani Transmission, Adani Total Gas, and Adani Enterprises might see the heaviest outflow among all.

Earlier, MSCI Inc said it has received feedback from a range of market participants concerning the eligibility and free float determination of specific securities associated with the Adani Group for the MSCI Global Investable Market Indexes (GIMI).

MSCI defines the free float of a security as the proportion of shares outstanding that is considered available for purchase in the public equity markets by international investors.

In the morning session, the 30-share BSE Sensex was trading 139.83 points or 0.23 per cent lower at 60,666.39 points.

The group's stocks have lost around Rs 9.4 lakh crore or about 49 per cent of their combined market capitalisation since January 24, when a US-based short-seller Hindenburg Research came out with its adverse report about the Adani Group.