Ralf Dahrendorf constructed a theory of class, conflict, and power that drew heavily on Weber. Influences from Marx are also discernible, even though he was critical of Marx.
Interactive World Wide Web Notes
Ed Grabb, fragment on Dahrendorf (pp. 116-123) in Chapter 6, "Recent Perspectives on Social Inequality", in Theories of Social Inequality. 3rd ed. 1996.
Ralf Dahrendorf, Class and Class Conflict in Industrial Society. Stanford University Press, 1959, especially Part Two, "Toward a Sociological Theory of Conflict in Industrial Society".