The Tata Trusts are publicly divided over plans to merge group companies into Tata Sons. Trustees Noel Tata and Venu Srinivasan said in a joint letter on September 30 that they were not consulted on an earlier letter backing the merger.

The September 28 letter had supported merging Tata Electronics Systems Solutions and Tata Consulting Engineers into Tata Sons. The September 30 letter distances two trustees from that position.

The dispute centres on the future shape of the Tata group. The proposed mergers would consolidate key businesses directly under the holding company.

The disagreement comes weeks after the RBI's September 11 decision to keep Tata Sons in the NBFC-Upper Layer, a classification that carries stricter regulatory norms.

The RBI tag limits what the group can do with its structure and has been a source of tension. Some in the group have explored options to avoid the classification.

The public split between trustees is unusual for the Tata group, which has traditionally presented a united front on strategic matters.

What happens next will depend on whether the trustees can reach consensus. The trusts hold a controlling stake in Tata Sons, giving them decisive influence.