Gerring had a long diplomatic career, beginning with postings in Hamburg, Moscow, and Budapest before becoming a second secretary at the Ministry for Foreign Affairs in 1947.
He held key roles in trade negotiations and UN delegations before serving in embassies across Washington, D.C., Ankara, Bern, and Bonn.
He was later appointed ambassador to Sofia, Baghdad, Kuwait City, and Wellington, also overseeing relations with Fiji, Tonga, and Western Samoa.
[1] He was a member of the Swedish-Hungarian government commission in 1948 and acted as a representative in trade negotiations with Bulgaria (1947 and 1949), Hungary (1947), and Yugoslavia (1948 and 1949).
[1][3] He then returned to the Ministry for Foreign Affairs in 1975 and was appointed ambassador to Wellington (also accredited to Fiji, Tonga, and Western Samoa) from 1979 to 1982.