Dr O'Reilly, 61, will stay on as chairman for three more years, but will not hold an executive title at the company. William R Johnson, 48, has been groomed to succeed Dr O'Reilly and takes over as chief executive.
Dr O'Reilly is also chairman of Independent Newspapers, the Irish group which owns 46 per cent of Newspaper Publishing, publisher of The Independent.
Dr O'Reilly was appointed chief executive of Heinz in 1979 and in October 1995 identified Mr Johnson to Heinz's board as his likely successor. Mr Johnson was appointed president and chief operating officer the following June. In September 1996, Dr O'Reilly announced that Heinz would undertake a thorough review of its global operations to further improve growth and productivity. Six months later Dr O'Reilly and Mr Johnson launched Project Millennia, the company's largest ever reorganisation, designed to produce annual earnings of 10 to 12 per cent into the 21st century and rationalise global manufacturing.
In the past year and a half, Heinz has sold off some Heinz businesses and bought new ones to concentrate on tuna, baby food, diet food, restaurant food, pet food and ketchup. In a statement, Dr O'Reilly called Johnson "an outstanding leader for the 21st century".