Abstract: The mounting frame arrangement is assembled from profile frame sections and connectors and is used for control panel assemblies, for component racks and holders, in household wiring, for equipment cabinets, and the like. On the four-sided (preferably square) hollow profile, one side has a longitudinal slit and at least the two adjoining sides each have openings opposite one another and distributed at regular intervals. The disconnectable connectors have two pairs of legs opposite one another and spaced apart by an adjustable distance, which are insertable in a form-locking manner into the interior of the profile. By being spread apart by spreader devices, the legs are made to contact opposed inside walls of the profile. At the same time, as locking means for preventing longitudinal displacement, detent protrusions come to engage the openings. A transverse groove for the same purpose is also possible on the outsides of the legs and on the inside of the profile.