This major category includes establishments engaged in finance or insurance.
Literal
This major-classification [to-には], finance-industry or insurance-industry [object-を] operating establishments [subject-が] classified.
Bureaucratic classification language. 大分類 (major classification) is from the Japanese Standard Industrial Classification system. 又は (or) is the formal disjunction, more official than または. 営む (to operate/conduct) is a formal verb for running a business. 分類される is the passive: 'are classified.'