Deputy chairman Roy Brown is to act as interim chairman. Chief executive, David Bennett, who has been ill for some time, returns to work on 6 May.
Brown said: “It was with shock and sadness that we learned of Derek’s sudden and unexpected death and our thoughts are with his family.
“Derek made an outstanding contribution to British business and was a well-known figure in the City; he was a pleasure to work with.”
Sir Derek, knighted in 2004, will be remembered for his report, The Role and Effectiveness of Non-Executive Directors. This was commissioned by the government in 2002 and established the ”combined code,” under which companies should have a majority of independent directors and should not ordinarily appoint the chief executive officer as chairman.