The article analyses the major external and internal factors contributing to instability market economy in general and the work of the diversified enterprises in particular. The authors show the role and importance of strategic planning for the long-term development of domestic diversified companies. The article identifies the key features of strategic planning for these enterprises in conditions of instability. The authors prove the necessity of creation of the system of integrated corporate planning. The result of the operation of this system should be a special set of planning documents, which occupies a leading role in the overall strategic plan. The basis of such a plan should be chosen a strategy of diversification. The main instrument for the implementation of the diversification strategy is integration. Penetration of corporations in other industries is carried out primarily through acquisitions, mergers and takeovers of enterprises in these sectors. Use a how to integrate predetermines the kind elected diversification strategy. With this in mind, the authors propose the classification of main varieties of diversification strategy, implemented by major companies. With regard to strategies of vertical, horizontal and conglomerate diversification examines their specificity and possible areas of application. Formulate practical recommendations on the application of these strategies in unstable conditions. The article analyses the processes of the general organization of strategic planning and the development of specific sets of different planning documents. Showing examples of application possibilities in these processes technology road mapping. Defined sequence and analysis of the major phases of operational management process implementation strategies and plans. The authors substantiate methodological approaches to the analysis of the effectiveness of the implementation of the strategies and plans on basic steps to implement them. Due to the need to create a special control system of diversified companies for emergency management.