Originally Posted by Mr_Anderson
Well at least you have now come back to clarify your position, Delete. So now allow me to address your points:
Stane wanted to be head of the company (kind of alluded to in the award presentation - he had control of the company before Tony was of an age where he could handle it), so he could sell arms to anyone. As seen later in the film, he was willing to deal with anyone, something even Stark wouldn't do.
It is revealed that Stane paid the Ten Rings members to kill Stark, but they realized who Stark was and demanded a much higher price
That, and Stane also seemed to have eyes for Pepper, who obviously was madly in love with Stark.