Shares of listed Tata Group companies lost about $3.2 billion in combined market value on Friday as investors responded to a widening dispute over Tata Sons, the group's holding company. The selloff followed the board's move toward complying with Reserve Bank of India rules that could require a listing and its decision to extend Chairman N. Chandrasekaran's term by five years. Tata Trusts, which owns 66% of Tata Sons, opposed both measures, calling Chandrasekaran's reappointment "illegal" under the company's articles. The disagreement has raised questions about governance, succession planning and the allocation of capital between Tata Sons' philanthropic obligations and investment needs. Tata Chemicals fell 9.57%, while Tata Consultancy Services declined 2.98%; Tata Capital was among the few gainers, rising 1.12%.