In 1991, Nationale-Nederlanden merged with the national postal bank, NMB Postbank to form the Internationale Nederlanden Group (ING). The merger provided Nationale-Nederlanden with a large additional distribution channel. Through strategic acquisitions across the US, Asia and Europe, ING grew into one of the world’s largest bancassurers. In the post-Cold War era of the early 1990s, ING launched more greenfield insurance businesses across Central Europe (Hungary, Czech Republic, Poland, Slovakia, Romania).

The 2008 global financial crisis had a major impact on ING, forcing it to apply for support from the Dutch government. Partly as a result of this, the European Commission forced ING to split its banking and insurance businesses and sell certain business activities. The remaining insurance business, which now comprises activities in Europe and Japan, was renamed NN Group and prepared for a public listing.