This research provides an in-depth analysis of the most influential industry wide factors of the telecommunication industry, which has experienced enormous changes, resulting from deregulation policies and technological advancement. Particularly, it points toward the determination of how changes in environmental forces and the interaction between them may create different conditions of task environment for firms competing within the same industry across countries under study. Further, we identified dimensions of task environment, which captured market concentration and task ambiguity determined at different stages of industry development, and finally their influence on performance. The empirical analysis indicates a statistically significant relationship between the different combination of market concentration and task ambiguity and the variations of performance outcomes. Our results support the classical model of the influences of industry structure on performance and offer significant theoretical implications on how the performance of telecommunication industry was influenced by technological innovation and deregulation policies through the changes in market concentration and task ambiguity. Notably, this research attempts to fill the need for more empirical studies and to quantify each of the industry forces, which is crucial to developing deeper knowledge of key environmental and strategic issues affecting the industry in question.