Conn served as chief executive downstream, of BP from 2007 until 2014 and was a main board director from 2004 to 2014.
In addition to leading Downstream, Conn also had group regional responsibility for Europe, Asia and Southern Africa.
Conn spent 29 years at BP, with leadership roles in oil trading, marketing, refining and petrochemicals, and E&P.
In July 2019 Centrica announced Conn would be stepping down from his post and retire from the company's board in 2020.
Conn told the Today programme it was "a natural time to hand over" as Centrica had reported a pre-tax loss of £446m in the six months to June.