The utility of Twitter as a medium for public engagement with news events has been well documented. Research has particularly highlighted the importance of Twitter as a space for the rapid assembly of ad hoc publics (Bruns & Burgess, 2015) around breaking news events, aided also by the availability of hashtags as a flexible mechanism for collecting all tweets marked as relevant to a specific topic (Rambukkana, 2015). In this, Twitter arguably even surpasses Facebook, as its flat, non-reciprocal, weak-tie network facilitates the dissemination of news more effectively than the hierarchical, reciprocal, strong-tie structure implemented by Facebook (Dewan & Kumaraguru, 2014). Much less is known about the platform’s performance in day-to-day news sharing and the news engagement practices of users outside of periods of heightened attention. Addressing this gap in the literature, this paper presents the first results from a major, long-term, internationally comparative study of news sharing on Twitter. Gathering Twitter data since mid-2012, we have managed – within the limitations set by the public Twitter API – to capture all tweets linking to a large selection of news sites in Australia, Germany, and the Nordic countries; our analysis of these data shows the distribution of attention to these sites, the dynamics of such marketshare over time, and the structure of each nation’s news-sharing user populations on Twitter, as well as comparing these patterns across the countries against the backdrop of their respective media ecologies.