Line-guiding channel arrangement with two fire-protected channels arranged adjacent to one another on the face side, in each case with a base and two side walls (3, 3.1) formed on the base and following the longitudinal extension of the channel, each with a cover connection rail (5, 5.1), wherein the cover connection rails (5, 5.1), starting from an upper termination of the channels, are configured so as to project into the channel interior, as well as a cover which can be secured to the cover connection rails (5, 5.1), wherein the base and the side walls (3, 3.1) are provided with an intumescent material layer, and with a joint seal for sealing the joint gap between the fire-protected channels arranged adjacent to one another, wherein the joint seal is configured as an interior seal, and these two side walls (8, 8.1) comprise a base part and a cover part, which in each case carry on the outside a sealing material (13, 13.1,18, 20) extending over the joint gap, said side parts (8, 8.1) carrying on their longitudinal side, facing away from the base of the fire-protected channel, a fit element (12, 12.1) for forming contact with the cover connection rails (5, 5.1), and, in the region of their base-side longitudinal side, at least one locking tab (16, 16.1) formed on the base side and projecting to the interior of the channel, wherein the cover connection rail (5, 5.1) is configured as far as possible in a U-shape, with its opening pointing upwards, and comprises a wall, free of intumescent material and with an outer side, wherein the side parts (8, 8.1) carry the fit element for forming contact with the outer side of the wall which is free of intumescent material, wherein the fit element (12, 12.1) is configured at the side parts (8, 8.1) as a U-shaped angled part of the end section of the side parts (8, 8.1), and wherein the fit element (12, 12.1) is configured in its dimensions such that the sealing material (13, 13.1, 18, 20), carried on the rear side by the side part (8, 8.1), after the introduction of the fit element (12, 12.1) of the side part (8, 8.1) into the side part receiving aperture (14, 14.1) of the fire-protected channel takes effect under preliminary tension against the inner side of the side wall (3, 3.1) of the fire-protected channel, and wherein the fit element (12, 12.1) of the side part (8, 8.1) of the joint seal takes effect with preliminary tension against the outer side of the cover connection rails (5, 5.1) which is free of intumescent material, and a region, not shown, of the side parts (8, 8.1) extends outwards over a termination part, facing the base of the fire-protected channel, of the at least one locking tab (16, 16.1), and forms a contact for longitudinal-side face surfaces of the base part, which is mounted between the side parts, said base part engaging beneath the at least one locking tab (16, 16.1) of each side part (8, 8.1), and is supported at the contact points of the side parts (8, 8.1), and the said cover part is a cover plate, extending over the width of the cover-side opening of the fire-protected channel, which is supported in each case by at least one support extension element (22, 22.1) on an upper-side face surface of the cover connection rails (5, 5.1).