Few foreign companies operate in Tehran, due to the government's complex international relations. But prior to the 1979 Revolution, many foreign companies were active in Iran. Tehran's present-day modern industries include the manufacturing of automobiles, electronics and electrical equipment, weaponry, textiles, sugar, cement, and chemical products. It is also a leading centre for the sale of carpets and furniture. The oil refining companies of Pars Oil, Speedy, and Behran are based in Tehran.