Leo George has been promoted to head of sustainable ownership at RPMI Railpen after eight years working for the £25bn fund as an investment manager.
George will take over from Deborah Gilshan, who is leaving for Standard Life Investments at the end of the month.
He will be responsible for implementing sustainable ownership considerations in the fund's investments.
George said sustainable ownership was vital to secure pensions in the long term.
"I am delighted to have the opportunity to continue Railpen's work in this area," he said. "Sustainable ownership remains an integral part of Railpen's investment approach to achieve the trustees' mission to pay pensions securely, affordably and sustainably."
Investment director Ciarán Barr added: "We are very pleased that we have someone of Leo's considerable experience to run our sustainable ownership team. I look forward to working with Leo as we continue to place sustainable ownership considerations at the heart of our investment decision-making."
George joined RPMI Railpen as an investment manager in 2008, and prior to that he was at Buck Consultants.
The government has confirmed the current interim chairwoman of The Pensions Ombudsman (TPO), Caroline Rookes, will continue the role in a permanent capacity.
The Pensions Management Institute (PMI) has appointed three non-executive directors and an executive director to its board.
Former Financial Regulators Complaints Commissioner Antony Townsend is to become chair of an expanded Determinations Panel at The Pensions Regulator (TPR).
Six members of Ross Trustees’ pension trustee and support teams have been promoted into new roles.