He was born in Kristiania as a son of businessperson Christian Strøm Steen (1854–1932) and Lilli Bing (1865–1935).
In 1925 he married Wencke Mowinckel Wetlesen, daughter of an explosives company executive.
[1] He took commercial education in Norway and abroad, and was hired in the family company Steen & Strøm in 1919.
[3] Together with his first cousin Erling Steen and Eyvind Strøm, who both too entered the company in the 1910s, he took over the leadership in the 1930s.
He resided at Gjettum farm since 1932, and was a member of Bærum municipal council from 1948 to 1951,[3] elected on a joint list of the Conservative and Agrarian parties.