This article discusses 'another' internationalisation of higher education through the lens of the 'third mission' of engagement from a Global South viewpoint. It recontextualises internationalisation and the third mission through the meanings and practices of university extension in Latin America. Within a Global North perspective, internationalisation of the third mission is under-studied, compared to the internationalisation of teaching and research. We offer a case study of the Montevideo Group University Association (Spanish acronym: AUGM), an association of Latin American public universities promoting academic exchange in teaching, research and extension. We further our analysis and discussion through a within-case analysis of Uruguay's Udelar, the eponymous founding location of AUGM. At a moment of radical, debilitating global and national marketisation and privatisation focused on the individual, the case of AUGM's internationalisation of regional public extension is complemented by Udelar's case-within-a-case of extension, tying widened higher education access to national democratic reforms.