Shares of Tata Group companies rallied by as much as 14% on Thursday as investors cheered reports that the Tata Sons board had approved plans to list the holding company, potentially paving the way for one of India’s biggest-ever initial public offerings.

The rally gathered momentum in late-afternoon trade following reports that the board had also reappointed N Chandrasekaran, who was due to step down next year, for another five-year term. Tata Sons confirmed both developments in a statement issued after market hours.

Tata Chemicals led the surge, jumping 13.5% intraday to Rs 831 on the BSE before surrendering some gains to close 6.6% higher at Rs 780.40. Tata Investment Corporation, TRF and Tata Motors Passenger Vehicles were among the other major gainers.

Expectations of value unlocking from a Tata Sons listing have put the spotlight particularly on listed Tata companies that own stakes in the holding company.

A potential listing could unlock value for Tata Chemicals, Saurabh Jain and Sriharsha Pappu, analysts at HSBC Global Investment Research, said in a September 14 report. Seven listed Tata group companies collectively own nearly 12% of Tata Sons.

The excitement spilled over to Shapoorji Pallonji (SP) Group companies, with Afcons Infrastructure gaining 3.31%, Vascon Engineers 3.32% and Gokak Textiles 9.24%.

Thursday’s gains extended a rally that began earlier this week after the Reserve Bank of India rejected Tata Sons’ request to surrender its NBFC registration, reviving expectations that the holding company would have to proceed with a stock market listing.

On September 15, Tata and SP Group stocks had surged by as much as 20%. Tata Chemicals jumped 20% during the session, while Tata Investment Corporation gained 10%. Afcons Infrastructure and Forbes & Company also climbed as much as 20% intraday before paring gains.

A listing could also have significant implications for the SP Group, Tata Sons’ largest shareholder outside the Tata Trusts. The group owns 18.4% of Tata Sons and has been exploring ways to monetise its holding to raise funds and reduce high-cost debt.

Brokerages have estimated Tata Sons’ market value at around Rs 12.5-13 lakh crore, underscoring the potential scale of any listing.

“Our analysis, based on publicly available information, implies a total market value for Tata Sons of Rs 13 lakh crore,” the HSBC analysts said.