[dstein]

Common stock only grants you a claim on the equity of a company. As a shareholder you usually get to vote who becomes a member of the board of directors and that's about it.

To gain decision control of a public company the OP will need to conduct a hostile takeover and probably take it private. Better get your checkbook out.

[carbocation]

This makes much more sense; thanks for the clarification. Conclusion: if you can buy the bigger company outright and take it private, then you can make it do business with the smaller company that you also own outright. Not particularly exciting.