Maurice Frère graduated as a commercial engineer at the École de Commerce Solvay.
During the years between World War I and II, he participated as an expert in several conferences concerning the problems of the German reparations and the general economic situation.
Shortly after the outbreak of World War II, he became administrator at the Banque d'Émission à Bruxelles, but in 1942 he resigned from that post.
The Belgian law of 28 July 1948 made provision for reinforcing the public character of the Bank, while guaranteeing its autonomy.
In 1946, he became chairman of the Board of Directors of the Bank for International Settlements (BIS) in Basel (Switzerland).