He became its director in 1967 and worked in various places including from Hong Kong, Taiwan, China, the United Kingdom, Malaysia and Australia throughout the years.
Henry was named senior managing director, while his uncle John resumed the chairmanship to ensure that the Keswicks did not lose control of the company.
[4] When Newbigging took over from Henry Keswick as the Jardine taipan in 1975, the company was undergoing a rapid decline in power and wealth.
Between 1975 and 1979, Jardine Matheson's profits grew at an annual rate of only 10 percent (a poor record for Hong Kong).
When he discovered a secret buyer had begun acquiring shares of Jardine Matheson stock in late 1980, many observers suspected that either Li or Pao (or worse, both) were attempting to purchase a large enough share in Jardine Matheson to win control over Hongkong Land.
Newbigging announced in early November that Jardine Matheson and Hongkong Land had agreed to increase their interests in each other, so as to make it impossible for any party to gain control of either company.
The defensive actions required during 1980 forced Jardine Matheson to sell its interest in Reunion Properties to raise cash.
Newbigging finally stepped down as senior managing director in June 1983, but retained the titular position of chairman.
He was the director of Rennies Consolidated Holdings Ltd, Sun Life & Provincial Holdings, Provincial Life Assurance Co Ltd, British Coal (formerly the National Coal Bd), CIN Management Ltd, United Meridian Corporation (USA), Market Board Corporation of Lloyd's, Merrill Lynch, Ocean Energy, Paccar, Academic Partnerships LLP Dallas USA.