After a careful analysis of Alpha (a company active in business A) and Beta (a company active in business B), you conclude that (i) synergies exist between Alpha and Beta and that (ii) synergies are one-sided (i.e. one party benefits but the other does not). Which governance mode would you recommend?
Synergies exist, hence there are benefits from jointly operating. However, all benefits go to one party. The other party has no incentive to contribute to the relationship. An acquisition provides a way to instruct the other party to contribute or to share the gains more equitably across the parties.