In 1978, the London-based Minster Assets investment group, which owned British Midland, decided to sell its stake. With the help of an entrepreneurial Californian dentist, Bishop raised £2.5 million to lead the management buy-out, and was subsequently appointed chairman: "I had to borrow the money from an American citizen. Most venture capitalists want a return of 40% to make up for all their other failures, and they want an exit strategy." From 1969 he was the key driving force behind the steady growth of the airline, which held eleven percent of the landing and take-off slots at London Heathrow Airport, second only to British Airways, and had a route network spanning Europe, North America, Asia and Africa.