New Delhi, Sept. 18 -- In a dramatic twist at the Tata Group, the board of Tata Sons on Thursday voted in favour of another five-year term for N. Chandrasekaran as the group holding company's chairman.

Controversy erupted over whether board member Venu Srinivasan had a right to vote. Redoubtably, assenting members based their decisions on earlier resolutions.

Tata Trusts, with a 66% stake in Tata Sons, called the vote "illegal," baring a deep split in trying times. Noel Tata, as the Trusts' chief, was outvoted and Chandrasekaran asked to reverse his earlier decision not to seek an extension.

The company whose leadership is being fought over may be headed for a public listing under a Reserve Bank of India rule for large financiers. Sinc...