Increasing a modules width

I have 2 modules published in the same location so that they are stacked on top of each other. I would like to leave the top module set at max width 33.33% as there are another two modules to the side of it, but I would like to increase the width of the lower module so that it takes the space up of 2 of the modules above it.

How would I go about doing this?

Thanks
George

Hi

That can be hard. I suppose You should use a different module position for this module below and use a template's layout tab to change widths of respective module positions.