Empirical studies have conérmed the prediction of theoretical models that contact in multiple markets may enhance érms' abilities to tacitly collude and consequently achieve higher prices and proéts. It has remained largely unexplored, however, how érms coordinate their actions. This paper identiées a method of pricing in the cellular telephone industry that seems to enable érms to coordinate their actions across markets. This pricing pattern is found to raise prices by approximately 7-10%, and cannot be attributed to a variety of noncooperative explanations.