How the Mistrys came to own 18.37% of Tata Sons: a partnership that began in 1930

The Shapoorji Pallonji (SP) Group owns 18.37% of Tata Sons, the holding company at the centre of the Tata group. That single fact explains most of what you are reading about a possible Tata Sons IPO in September 2026. What it does not explain is how a family of builders came to own almost a fifth of the most closely held company in Indian business.

The answer starts with a loan, not a share purchase — and it is nearly a century old.

1924–1926: a ₹2 crore loan to a struggling Tata group

In the mid-1920s the Tata group was under strain. Forbes India's account is that between 1924 and 1926 the financier Framroze Edulji Dinshaw lent ₹2 crore to help Tata Hydro and Tata Steel. In exchange he was promised a share of what Tata Sons made from those two companies: 25% of the Tata Steel earnings and 12.5% of the Tata Hydro earnings.

That promise did not work out as intended. The loan was eventually converted into equity instead — about 12.5% of Tata Sons itself. A lender had become an owner.

1930: Shapoorji Mistry buys the Dinshaw holding

Shapoorji Mistry was by then a well-known Mumbai builder. His firm put up buildings that are still landmarks in the city — the Reserve Bank of India building and the Taj Mahal Palace among them, and around the Fort area the old Hong Kong & Shanghai Bank, Grindlays, Standard Chartered and State Bank of India buildings.

In 1930 he bought the 12.5% Tata Sons holding from Dinshaw's heirs. It was a builder buying a financier's inheritance; no Tata sold him anything. He later bought the Tata Sons shares held by JRD Tata's siblings, which took the family above 18% — roughly where it still sits.

“In 1930, just a year after Pallonji Mistry was born, his father Shapoorji acquired the 12.5 percent stake from Dinshaw's heirs.”

1975 onwards: one family, one block of shares

Shapoorji died in 1975 and left the entire holding to his son, Pallonji Mistry, who held it for the rest of his life. Through those decades the relationship was quiet and close: the family had a seat at the Tata Sons board and almost never used its shareholding to pick a public fight. Pallonji Mistry died in 2022.

The stake today is held through two investment companies, Sterling Investments Corporation Private Limited (SICPL) and Cyrus Investments Private Limited (CIPL). Together they hold 18.37%.

The rest of the register

For scale, this is who owns Tata Sons:

• Tata Trusts — about 66%, mainly the Sir Dorabji Tata Trust (27.98%) and the Sir Ratan Tata Trust (23.56%).
• The Shapoorji Pallonji family — 18.37%, through SICPL and CIPL.
• Tata group companies — about 13%.
• Individuals, mostly members of the Tata family — the remainder.

Two owners therefore decide almost everything: a charitable block that answers to its trustees, and one family that answers to its lenders. They want different things from the same shares, which is the whole of the current dispute.

2011–2021: from partner to litigant

Cyrus Mistry, Pallonji's younger son, was named to succeed Ratan Tata at the head of Tata Sons in November 2011. He was removed as chairman in October 2016, and N Chandrasekaran took the chair in February 2017.

What followed was five years of litigation:

• December 2019 — the NCLAT ordered Mistry's reinstatement and held that the conversion of Tata Sons into a private limited company was illegal.
• January 2020 — the Supreme Court stayed that order.
• 26 March 2021 — the Supreme Court upheld Tata Sons' decision to remove him.

Cyrus Mistry died in a road accident in September 2022. His family lost the case, but not the shares: 18.37% of Tata Sons is still theirs, and it is still the largest holding outside the Trusts.

Why the history matters in 2026

A stake acquired in 1930 has become a problem of 2026 for one reason: it cannot easily be turned into money. Tata Sons is unlisted, so there is no market price and no obvious buyer for a block of this size. The SP Group has borrowed against the holding for years and would like to sell part of it; the Tata Trusts would prefer the company stay private.

That argument now has a regulator in the middle of it. We have covered the current fight, the RBI order and the ₹25,000 crore proposal on the table separately: read why the Tatas and the SP Group are fighting over a Tata Sons IPO.

If you are new to how a public issue works in the first place, start with what an IPO is, and see the IPO Center for issues that are actually open now.