AG in 1874 which became a global corporation before World War I. At the beginning of the 1980s the Hoechst AG was the largest pharmaceutical corporation in the world relating to its business volume and the Industriepark H�chst was known as "the pharmacy of the world". The Hoechst AG merged with Rh�ne-Poulenc to become Aventis in 1999 and in 2004 Aventis merged with Sanofi-Synth�labo to become Sanofi-Aventis. In 2005, around 22,000 people worked at Industriepark H�chst. In 2011, Ticona, an international manufacturer of engineering polymers, moved to Industriepark H�chst because it had to abandon its location in Kelsterbach due to its closeness to the newly constructed fourth runway at Frankfurt Airport.
Until the year 2000, when Deutsche Bahn moved to Berlin, the headquarters of Germany's national railway company were located in Frankfurt. Today, the Deutsche Bahn subsidiaries DB Fernverkehr, DB Regio, DB Stadtverkehr, DB Netz and the corporate development department of Deutsche Bahn are still based in Frankfurt.
In 2010, DB Schenker, the logistics subsidiary of Deutsche Bahn, announced that it would move its headquarters to Frankfurt in early 2012, together with 330 employees from offices in Berlin, Mainz and Essen.
Deutsche Telekom, the largest telecommunications company in Europe, is headquartered in Bonn, but its subsidiary T-Systems is based in Frankfurt.
COLT is a telecommunications company with its German headquarters based in Frankfurt.
Level 3 Communications is an internet service provider company with its German headquarters based in Frankfurt.
Frankfurt is an important location for electronic communication, especially the Internet. It is home to DE-CIX, the world's largest internet exchange point, and also the place where domain names are registered for the top-level-domain ".de".
Mainova is the largest regional energy supplier in Germany with about one million customers in Hesse. It provides electricity,
