Union Airways poster, 1937

As those who have the book The Aircraft of Air NZ and affiliates since 1940 know, Union Airways was from 1936 the largest New Zealand airline, and it began a scheduled interisland service on 16 January 1936. In 1938 it amalgamated with East Coast Airways which had begun in 1935. Both companies had financial backing from the Union Steam Ship Company which, as observed before, was the NZ equivalent of Canadian Pacific.  After WW2 in 1947 it was a major component in the formation of NAC.

For more on this subject including the Karoro aircraft, see the book.