The present investigation is devoted to development of new optimal design concepts that exploit the full potential of advanced composite materials in aircraft lateral wing upper covers. Three rib bays laminated composite panels with T, I and HAT-stiffeners are modelled with ANSYS and NASTRAN finite element codes to investigate their buckling behaviour in dependence on skin and stiffener lay-ups, stiffener height, stiffener top and root width. Due to the large dimension of numerical problems to be solved, an optimisation methodology is developed employing the method of experimental design and response surface technique. Weight optimisation problems are solved for laminated composite panels with three types of stiffeners, two stiffener pitches and four load levels taking into account manufacturing, repairability and damage tolerance requirements. Optimal results are verified using ANSYS shared-node and NASTRAN rigid-linked models.