David Maddison, managing director of RPMI, the executive arm of the Railways Pension Trustee Co., London, will retire June 30, a spokesman said.
Mr. Maddison's replacement has not yet been named, the spokesman said.
RPMI manages the £28 billion ($36 billion) in assets of Railways Pension Scheme, London.
"We would all like to thank (Mr. Maddison) for his long and dedicated service to RPMI, helping to shape the Railways Pension Scheme both during and after the privatization of the railways industry. His contribution to the scheme and our industry has been enormous," said John Chilman, chairman of Railways Pensions Trustee Co., in a news release.