The two companies did well through the bulk of the 20th century, despite difficulties for P&S during World War II. While both companies managed flavors and fragrances, Polak & Schwarz had particular strengths in flavors and van Ameringen-Haebler built a powerful reputation in fragrances. In 1958, the two companies announced their merger to become International Flavors & Fragrances Inc. IFF was listed on the New York Stock Exchange in 1964. It was cross listed to the Euronext Paris Market in 2015, becoming the first US-listed company to make use of Euronext Paris Fast Path process.