The governance dispute at Tata Sons intensified Tuesday as the Tata Trusts moved toward litigation over the reappointment of executive chairman Natarajan Chandrasekaran. Noel Tata, chairman of the Trusts, has declared the reappointment resolution null and void.

The Tata Trusts, which own roughly 66% of Tata Sons, have contested the procedural validity of board decisions. The Trusts include the Sir Dorabji Tata Trust and the Sir Ratan Tata Trust, the philanthropic bodies anchoring the group's ownership structure.

At issue is whether nominee directors representing the Trusts received adequate consultation before key board resolutions, including matters concerning Chandrasekaran's leadership and Tata Sons' potential public listing. Trustees believe their shareholder rights were bypassed, according to Indian business media.

A courtroom battle would mark the most serious internal conflict at Tata Sons since the acrimonious 2016 ouster of Cyrus Mistry, which triggered years of litigation reaching India's Supreme Court. Analysts at domestic brokerages warned that prolonged uncertainty could complicate the group's planned capital-raising and any stock market flotation of Tata Sons.

Tata Sons oversees operating companies including Tata Consultancy Services, Tata Motors and Air India, with combined revenues exceeding $150 billion. Neither the Tata Trusts nor Tata Sons issued a formal statement confirming that legal papers had been filed as of Tuesday.

"The board's resolutions must respect the will of the majority shareholder," a person aligned with the Trusts told reporters in Mumbai, describing the reappointment process as procedurally defective.