This paper develops a Trade Network Game (TNG) that combines evolution ary game play with endogenous partner selection. Resource-constrained buyers and sellers choose and refuse trade partners on the basis of continually updated expected payoffs. Partner selection takes place in accordance with a "deferred choice and refusal" mechanism that is shown to have interesting stability, optimality, and uniqueness properties. The iterated prisoner's dilemma strategies used by buyers and sellers to conduct their trades are evolved over time via a genetic algorithm that biases reproduction in favor of strategies that have been successful in past trades..