George Cowcher had indicated his intention to stand down in early June and his formal notice was accepted by the chamber’s board of directors when it met on June 16.
He has just returned from a planned holiday to the US and has agreed to leave with immediate effect.
The board has moved to strengthen the management by promoting head of information and representation, Chris Hobson, to director of policy and external affairs.
He will join the existing senior management team in responsibility for the day-to-day running of the chamber until a new chief executive is recruited.
Mr Cowcher said: “When I came to the East Midlands in 2006, I was appointed to create a regional chamber for the region which would have real clout and be able to work on behalf of the world class companies located here.
“That job is now almost complete and it is time for me to move on and look for a new challenge.
“I thank the many individuals, companies, organisations and colleagues who have helped me over the years.
“I wish the Chamber well for the future.”
Liz Fothergill, chamber president, paid tribute to Mr Cowcher and highlighted the work he carried out during his tenure.
She said: “On behalf of the chamber, its board of directors and staff, I’d like to place on the record my sincere thanks for the commitment, dedication and service George has given to the chamber – and to the local business community – in his time as chief executive.
“He successfully oversaw the merger between the former Derbyshire and Nottinghamshire Chambers of Commerce, which officially became DNCC in 2006, and was responsible for growing it into the second-largest chamber in the country. He then oversaw a further merger, when DNCC and its sister organisation in Leicestershire merged to form East Midlands Chamber and consolidated its position as the UK’s second-largest.
“George was also instrumental in bringing the four principal local authorities in Derby, Derbyshire, Nottingham and Nottinghamshire together to establish the D2N2 Local Enterprise Partnership in 2010.
“He has been a great advocate, both locally and nationally, of the East Midlands business community and has dedicated a great deal of his time to helping to boost the region’s presence in the global marketplace during his time as chairman of the British Chambers of Commerce’s International Trade Group.
“We wish him all the best for the future.”