Tata Sons, the holding company for India’s largest conglomerate, is considering an historic revamp of its leadership structure by creating a chief executive officer’s role to help improve corporate governance, people engaged in the deliberations said. Under the plan being proposed, the CEO will guide the sprawling businesses of the 153-year-old Tata empire, while the chairman will oversee the chief executive on behalf of shareholders, the people said, asking not to be identified discussing private information. The approval of Ratan Tata -- the octogenarian chairman of controlling owner Tata Trusts -- is seen as key to implementing the change, they said.