This paper considers the allocation of excess supply among agents on the long side of the market from the standpoint of cooperative game theory, Under the no-forced-trading hypothesis, supply actually traded equals market demand. Suppose a winning coalition of sellers can fulfill their desired sales, up to the limit of market demand. The main results characterize the value allocations of the ensuing market rationing games. In particular, the endogenous hierarchic rationing mechanism of Heller and Starr arises when power is distributed evenly among sellers.