Panels Three Four Layout is a grid based, adaptive layout for Panels module. It's similar to the flexible layout that you can find in Panels' core, with the exception that in adaptive layout the final page is rendered based on how the panes are connected to the panel grid. It means that the panes automatically expand to the right to fully occupy empty cells in the grid. Thanks to this behaviour very flexible auto-constructed layouts are possible.
The grid consist of the two stacked spaces, topmost space is 3x3 and bottom space is 4x4.
Download, install and enable the module and look for new layout on Panels' creation or edit workflow.