The invention relates to a method of separating solids from a gas flow in a fluidized catalytic process and to a cyclone assembly suited for use in a fluidized catalytic process. According to the invention, the gas flow of the process carrying the suspended solids is passed into a separation assembly, wherein the solids are separated from the gaseous phase under the effect of the centrifugal force, whereby a multiport cyclone is used as the separation assembly, into which the gas flow to be treated is passed via an inlet nozzle having an axially annular cross section. The use of the multiport cyclone, e.g., in an FCC process give significant advantages in flow dynamics and process engineering over conventional arrangements and generally used single-port cyclones.