Contingent ownership structures are prevalent in joint ventures. We offer an explanation based on the investment incentives provided by such an arrangement. We consider a holdup problem in which two parties make relationship-specific investments sequentially to generate a joint surplus in the future. In our model, the following ownership structure implements first-best investments: one party owns the firm initially, while the other party has the option to buy the firm at a set price at a later date. This result is robust to the possibility of renegotiation and uncertainty.