I study a dynamic one-sided-offer bargaining model between a seller and a buyer under incomplete information. The seller knows the quality of his product while the buyer does not. During bargaining, the seller randomly receives an outside option, the value of which depends on the hidden quality. If the outside option is sufficiently important, there is an equilibrium in which the uninformed buyer fails to learn the quality and continues to make the same randomized offer throughout the bargaining process. As a result, the equilibrium behavior produces an outcome path that resembles the outcome of a bargaining deadlock and its resolution. The equilibrium with deadlock has inefficient outcomes such as a delay in reaching an agreement and a breakdown in negotiations. Bargaining inefficiencies do not vanish even with frequent offers, and they may exist when there is no static adverse selection problem. Under stronger parametric assumptions, the equilibrium with deadlock is unique under a monotonicity criterion, and all equilibria exhibit inefficient outcomes.