Stewart joined the Hong Kong and Shanghai Banking Corporation in around 1929 and worked for it for forty years.
From 1952 to 1953, he was chief accountant of the Bank, and as such Hong Kong banknotes displayed his signature.
During Turner's absence in 1961, Stewart was appointed provisionally to the Executive Council of Hong Kong for a brief period of time.
[1] Stewart later sat on the board of the British Bank of the Middle East in which he retired in 1969.
[5] In 1964, Stewart was also appointed chairman of the London Committee of the Hongkong and Shanghai Banking Corporation.