  We study bilateral trade with interdependent values as an informed-principal
problem. The mechanism-selection game has multiple equilibria that differ with
respect to principal's payoff and trading surplus. We characterize the
equilibrium that is worst for every type of principal, and characterize the
conditions under which there are no equilibria with different payoffs for the
principal. We also show that this is the unique equilibrium that survives the
intuitive criterion.
