Noel Tata has stepped down from the boards of six Tata Group companies as he turned 70, in one of the biggest boardroom changes at the group in years.

Tata retired as chairman and director of Tata Investment Corporation at the close of business on November 11, ending more than 16 years as chairman of the group’s investment arm. He joined the company’s board in June 2004 and became chairman in June 2010. He has been named Chairman Emeritus.

Bahram Vakil, co-founder of law firm AZB & Partners and the company’s vice-chairman, takes over as chairman of Tata Investment Corporation from November 12.

The change follows the Tata Group’s governance rules, which require non-executive directors to retire when they turn 70. Noel Tata was born on November 12, 1956, and turned 70 on Thursday.

The exits go well beyond one company. Tata is giving up four chairmanships and two vice-chairmanships: he will no longer be non-executive chairman of Trent, Voltas, Tata Investment Corporation and Tata International, and he is stepping down as vice-chairman of Tata Steel and Titan Company.

Bahram Vakil will also take over as chairman of Trent. Other successors have been named across the group companies.

Tata had signalled the move in advance. He told shareholders at Trent’s annual general meeting in June that it would be his last as chairman.

The change does not mean he is leaving the Tata Group. He continues as chairman of Tata Trusts, the group’s philanthropic holding body, and remains a Tata Trusts nominee director on the board of Tata Sons, the group’s main holding company.

The transition was confirmed in a stock exchange filing on Wednesday. It is part of a planned governance process, and the companies said it has no connection with the ongoing differences between Tata Trusts and Tata Sons over the group’s leadership and governance.