German-British sociologist Ralf Dahrendorf, 80, a knighted researcher whose work examined social classes in modern society, has died.

The Social Science Research Center in Berlin, where Mr. Dahrendorf was a research professor, said he died Wednesday at a university clinic in Cologne.

Born in Hamburg in 1929, Mr. Dahrendorf taught at numerous schools and universities in Germany and Britain. He was elected to the German parliament in 1969 for the pro-business Free Democrats. He became a British citizen in 1988 and was knighted in 1993.

Much of the work of Mr. Dahrendorf, who was a political scientist and economist as well as a sociologist, examined class and integration. His many books included his best-known work, Class and Class Conflict in Industrial Society, which he wrote in 1959.

- AP