The complementary parts of food products destined to be coupled together are located on the frontal surfaces of half-moulds travelling on two different loop conveyor lines. The first conveyor line extends, at least partially, above the second, so to be included within the surface area occupied by the second line itself. Spatial occupation is further reduced since, downstream to the coupling station, the coupled half-moulds travel with the same spacing step that they had before coupling, with additional advantages in terms of energy absorption and advancing velocity in a successive thermal conditioning station, such as a refrigerating tunnel. One of the half-moulds can be removed upstream to the thermal conditioning station, resulting in an additional reduction in energy absorption since needless subjecting of the half-mould to the thermal cycle to which the products are subjected is avoided.
