[1] Petrén carried out court service in Vemmenhögs, Ljunits and Herrestad Hundred's judicial districts (Vemmenhögs, Ljunits och Herrestads häraders domsaga) from 1935 to 1938.

[2] He worked as an extra legal clerk (fiskal) in the Scania and Blekinge Court of Appeal in 1939,[2] as court secretary in Frosta and Eslöv judicial districts (Frosta och Eslövs domsaga) from 1942 to 1944, and as assessor in 1952 (temporary officer in 1946).

[1] Petrén was secretary in the 1948 Vagrancy Inquiry (1948 års lösdriveriutredning) in 1948, in the Second Law Committee in 1949, and had legislative assignments from 1950 to 1953.

Petrén was a member of the National Export Credits Guarantee Board from 1955 to 1957 (vice chairman from 1956 to 1957), in the committee on questions related to the right to carry on business [in Sweden] from 1958 to 1962, chairman of the Oil Protection Inquiry (oljeskyddsutredningen) from 1963 to 1965, the Swedish National Association against Heart and Lung Diseases (Svenska nationalföreningen mot hjärt- och lungsjukdomar) from 1972, member of the Council on Legislation from 1980 to 1981 and occasionally from 1982 to 1984.

Edling died on 12 October 1990, in Stockholm, three months after his wife passed away.