Shapoorji Pallonji Group companies, Sterling & Wilson Solar Ltd and Forbes & Co Ltd on Wednesday surged after the group unexpectedly said it will end its seven decades-long partnership with the Tata group.

Shares of Sterling & Wilson Solar hit 20% upper circuit, its biggest single day gains since August 2019 while Forbes & Co Ltd hit 5% upper circuit.

The Shapoorji Pallonji group’s decision came soon after the Tata group on Tuesday told the Supreme Court that it was ready to buy the Mistry family’s stake in Tata Sons at current market value.

As of 30 June, Shapoorji Pallonji group owns 50.6% stake in Sterling & Wilson and 72.6% in Forbes.

The cash-strapped Shapoorji Pallonji group has been looking to raise funds by pledging its stake in Tata Sons, estimated to be worth 1.5 trillion, to pay down debt but the move was blocked by the Tata group, which feared that the stake may fall into the hands of hostile investors who could threaten its control over group companies.