Background
He was born in Sandefjord as a son of ship-owner Anton Fredrik Klaveness (1874–1958) and Therese Grøn (1875–1948).
He was born in Sandefjord as a son of ship-owner Anton Fredrik Klaveness (1874–1958) and Therese Grøn (1875–1948).
He competed in equestrianism at the 1928 Summer Olympics in Amsterdam, where he placed 32nd in individual show jumping and 11th in the team contest. He later chaired the Norwegian Jockey Club. After middle school, commerce school (Oslo Handelsgymnasium) and business training abroad he was hired in his father"s shipping company A. F. Klaveness & Company in 1923.
He also became a board member in 1934 and chaired the board from 1947.
He chaired the boards of Forsikringsselskapet Vega and Norske Shell, the supervisory councils of Otto Thoresen Shipping Company, Sydvaranger, Andresens Bank and Det Norske Veritas.
He was a national and central board member of the Norwegian Shipowners" Association, chaired the Norwegian board of Nordisk Defence Club and Framnæs Mekaniske Værksted. Klaveness was also an elected member of Bærum municipal council from 1935 to 1937.