Arnhold and S. Bleichroeder was a New York-based investment bank, originally formed in Germany by 1931 by merger of Arnhold Brothers and S. Bleichröder and relocated to the United States in 1937. It remained as a fund management company under the control of the Kellen and Arnhold families until December 2015, when majority ownership was sold to the Blackstone Group LP and Corsair Capital LLC, led by Simpson Thacher & Bartlett.[1]