Warburg Pincus LLC is a global private equity firm, headquartered in New York City, with offices in the United States, Europe, Brazil, China, Southeast Asia and India. Warburg has been a private equity investor since 1966. The firm currently has over 100 billion in over 1,000 companies in 40 countries. Warburg Pincus invested in the information and communication technology sectors, including investments in Avaya, Bharti Tele-Ventures, Harbour Networks, NeuStar, PayScale, and Telcordia. In June 2023, Warburg Pincus was ranked 10th in Private Equity International's PEI 300 ranking of the largest private equity firms in the world. In 1939, Eric Warburg of the Warburg banking family founded a company under the name E.M. Warburg & Co. Its first address was 52 William Street, New York, the Kuhn Loeb building. Throughout the early post-war period, the firm was a small office of 20 employees. In 1966, E.M. Warburg merged with Lionel I. Pincus & Co, forming a new company that eventually became known as E.M. Warburg, Pincus & Co. In 1965, when Eric Warburg retired to Germany, control was handed to Lionel Pincus, a partner in the Ladenburg Thalmann investment bank, and the working language of the office switched from German to English. In 1967, John Vogelstein, a former partner at Lazard Freres, joined Pincus to build the firm. Together they developed a strategy of investing in diversified companies of various sizes rather than focusing on start-ups. Pincus was the founder and chairman while Vogelstein was vice chairman and then president. Pincus and Vogelstein ran the company until 2002, when they stepped down and appointed Charles Kaye and Joseph P. Landy as co-presidents. Pincus died in 2009.