Legal & General's chief financial officer Mark Gregory is leaving the business after 17 years.
He will retire from the group on 31 January, although will remain on hand until a successor is appointed to "ensure there is a smooth transition".
Gregory has been an executive director on the board for the last seven years, initially as chief executive of the savings business before becoming group finance boss.
He said: "My time since becoming group chief financial officer has coincided with a period of significant regulatory change resulting from the introduction of Solvency II and it is pleasing to have secured approval for all our applications.
"Whilst a difficult decision, I have decided that next January is a good time for me to be retiring from the group. In the meantime, I look forward to presenting the full-year results in March and helping to deliver the strategy over the coming year. "
Nigel Wilson, group chief executive, added: "Mark has made a terrific contribution in the various and important roles he has undertaken at Legal & General. He has also been a great partner and I thoroughly enjoy working with him. I thank him immensely."