Bertelman's career in the Swedish Ministry for Foreign Affairs began in 1971 and included a variety of roles.

Early on, he served in Hanoi and London, before holding positions as counselor in Moscow and later as consul general in Leningrad.

He continued his ambassadorial career in Riga (2000–2003), Warsaw (2005–2008), and Moscow (2008–2012), where he presented his credentials to President Dmitry Medvedev in 2009.

[1] He attended Dartmouth College in the United States from 1965 to 1966, and received a Bachelor of Arts degree from Lund University in 1971.

[2] In October 2012, TeliaSonera assigned Bertelman to act as a strategic advisor in matters concerning the company's operations in Central Asia.