Mr Jewson will continue in post until a new chairman is appointed by the Archant board.
Mr Jewson said: “Richard has notified the board that due to a medical condition he will now not be able to commit sufficient time and energy to the role of chairman and can consequently no longer take up the position. Richard is also reducing his overall work commitments and has resigned as a non-executive director of Archant.
“Clearly this is disappointing and unwelcome news both for Richard and Archant. We wish him well and thank him for his significant contribution whilst on the board.
“The board has considered its next steps and has decided to appoint an external chairman, the process for which has already begun. In the meantime, at the request of the board, I have agreed to remain as chairman.”
