The relevance of the issue is caused by the necessity to increase industrial enterprise operational efficiency using mathematically based manufacture modernization decision making method. The main aim of this study is to develop a decision making technique for industrial enterprise manufacture modernization. The arrangement is assumed to be proposed by a third-party developer. The enterprise is considered to operate as a mass production plant and an oligopoly member. The methods used in the study. System analysis is used to find the solution; in order to solve the entire problem the situation participants and their possible actions are identified and then used to construct a tree of outcomes; necessary data is collected and an industry demand and its enterprises' cost functions are estimated using simple linear regression; enterprises' optimal profits are evaluated using the game theory Cournot competition model. If there are no probabilities of participants' actions it is possible to make a decision under uncertainty. However if there are natural language expert appraisals of their values each outcome probability can be calculated and a decision under statistical uncertainty can be made by evaluation of those probabilities using fuzzy arithmetic. The decision making technique itself can be performed by maximizing average or most probable profit. The results. The developed method is applied to decide if a certain innovation should be acquired by a potash industry enterprise. OJSCs «Uralkali» and «Belaruskali» were chosen as potash industry members and for each of them the best courses of action under fuzzy probabilities variation were elaborated.