Richard Pennycook, CEO of the Co-operative Group, told the BBC that the group had been "let down" by its former management, but that recent changes to its structure and governance should rectify that situation..
According to Pennycook, the organisation had been "undermanaged" in the past.
"We let the co-operative movement down in a fairly significant way, after 150 proud years where the Co-op had a reputation for doing the right thing," he said on BBC Radio 5 Live
It now needs to become "better at business" and return to making profits, he cited: "Just applying good management disciplines and taking out costs can improve profitability."
According to Pennycook, the former Morrisons Finance Director, the "painful" process of selling some businesses to repair the balance sheet was necessary.
The Co-op was second to Tesco in the convenience food market, he said, and the quality of its products had noticeably increased: "We can absolutely compete with the best."
Mr Pennycook was appointed as the Co-op's interim chief executive early last year before assuming the role permanently and Allan Leighton, Chairman, is in the process of rebuilding the board after being appointed in February as its first independent chair.
His appointment followed the record £2.5bn loss for 2014 that was caused largely by a crisis in the Co-op’s banking business.