German-based Axel Springer is one of Europe’s biggest media houses. BERLIN—The German owner of Politico and other U.S. outlets announced Tuesday a restructuring of its domestic operation as part of a strategy to shift its focus to the U.S. and become a globally leading digital-only publisher. Axel Springer SE, one of Europe’s biggest media houses and the only one with a major U.S. presence, will slim down its corporate structure. It aims to boost earnings in its German media business by around 100 million euros, equivalent to $106.1 million, over the next three years, with a mid-term aim to shut down its print editions, the company said.