May I suggest you consider side by side display, with visual indicators of difference?
If you can elaborate what's important (change/discrepancies, seeing whether values are higher or lower, etc.), that would be helpful, but if I was to implement something based on the limited information provided, I would consider displaying the two tables side by side (assuming this is possible, example indicates four columns which isn't too much data overhead). The first table would be the "reference", whereas the second table's cells would be marked to indicate differences from the first (perhaps colored red for lower values and green for higher?) like so:
You may like to pair this with an easy method to swap companies, as well as some sort of primitive 'query builder' to allow users to only select columns that matter so as not to overwhelm them with information.
If using colors, you could also adjust the saturation of the cell coloration to correspond with how great the difference in value is.
This idea may or may not be appropriate depending on how your data is structured. If you choose this idea, you may need to adjust your colors to suit the visually impaired.
Based on Andrew Martin's comment regarding the visually impaired, you could consider a similar implementation of this idea, such as using small arrow icons in the cells to indicate differences instead of color.
Furthermore, as per his comment, these "difference indicators" may require a sentence clarifying their meaning, may convey unintended meaning to those unfamiliar with the interface, and may not be appropriate for every column/row.