Results of eight tests on long stiffened panels under axial compression until collapse are presented. The specimens are three-bay panels with associated plates made of very high tensile steel S690. Four different configurations are considered for the stiffeners, which are made of mild or high tensile steel for bar stiffeners and mild steel for L and U shape stiffeners. The influence of the stiffener’s geometry on the ultimate strength of the stiffened panels under compression is analyzed. This series of experiments belongs to an extended series of tests that include short and intermediate panels, which allows analyzing the effect of space framing on the strength of stiffened panels.