Background and Objectives: In today's world, there are various contracts and legal frameworks for commercial economic activities. One of the most important frameworks in this field is economic and financial agreements. These agreements provide regulations and guarantees for those private companies that pursue economic activities or specifically foreign direct investment. When a company or an individual wants to do business or invest in another country, there is always a risk that the funds will be nationalized or confiscated in some way by the host country. In order to protect economic agents/investors and in order to support economic activities, most countries sign economic and financial agreements. Logically, these agreements should be part of trade agreements, but they are usually implemented following a bilateral/multilateral or regional agreement between two/several countries. Therefore, most of the countries use Financial economic agreements to support and protect the rights of companies during their economic activities in other countries, while less developed countries conclude agreements with the intention of attracting more foreign economic activities and gaining a greater share in the competitive environment. Therefore, due to the importance of Financial economic agreements, the present research was considered with the aim of investigating the interactions between the rigidity and Rigidity of Financial economic agreements, the instability of the political system, and the Ownership structure. Materials and Methods: Data related to economic activities in the year 2022 for the period 2019 to 2022 multinational companies with an average of 4 new foreign investments per year were selected and collected with a final number of N = 116 and analyzed using paired logistic regression. Results: Regression was estimated in four models. In the first model, the three variables of instability of political system (PI), strength of treaties (TSTR) and PI * TSRT are not considered and without considering these three variables, only two variables of economic activity laws and population have a significant effect. In the second model, among the three main variables, only the variable of political system instability (PI) was included in the model, and its effect alone is not significant (Table 3, Model 2). However, again, the two variables of laws of economic activities and population are significant. In the third model, among the three main variables, only the variable of the strength of traders' economic agreements (TSTR) has been entered into the model, and again, statistically, the effect of the strength of financial economic agreements is not significant (model 3). However, again, the effect of two variables, laws of economic activities and population, are significant. In the fourth model, all three variables of political system instability (PI), strength of economic and financial agreements (TSTR) and interactive variable PI * TSRT have been entered into the model. Again, the two variables of laws of economic activities and population have a significant effect in this model. In addition, the interactive effect of PI * TSRT has become statistically significant, but the two variables of instability of the political system (PI) and strength of economic and financial agreements (TSTR) are not significant. Therefore, the interactive effect in model 4 shows that with the increase in the instability of the political system, very strict economic and financial agreements reverse the preference of multinational companies for minority ownership and make it more likely that multinational companies choose majority ownership. At higher levels of instability of the political system, greater strength in economic and financial agreements increases the possibility of increasing the choice of multinational companies from stocks. In other words, it is clear that stricter economic and financial agreements with increasing instability of the political system encourage multinational enterprises to choose majority ownership instead of minority ownership. Finally, by replacing the instability of the political system with two other indicators of political uncertainty in the host country, supplementary tests were conducted as follows: The instability of the political system has been replaced by Henize's Political Constraints Index (POLCON). For the political system instability variable, global governance indicators were used by reversing the political restrictions (POLCON-1). The Political Constraints Index (POLCON) captures a different aspect of a country's level of political stability, i. e., the probability of political tolerance/stability by directly measuring the feasibility of policy change based on the structure of the country's political institutions (e. g., the number of veto points). which evaluates the complex relationship between the number of attempts to change and the degree of restriction in the policy making of the legislative and executive powers. Equilibrium at all levels increases the possibility of policy change, thereby reducing the level of political constraints and increasing the capacity to draw conclusions from the government. Possible scores for the final measure of political constraints range from zero (most dangerous) to one (most restrictive). This measure was reversed (POLCON-1) to be consistent with the original test and a negative sign on the POLCON-1 coefficient is expected as a direct effect and a positive sign for the interaction term. Using economic freedom (inverse), an additional robustness test was implemented. Conclusion: The instability of the political system and the rigidity/stringency of Financial economic agreements in a non-interactive way did not have a significant effect on the choice of affiliated ownership, but in an interactive mode, with the increase in the instability o the political system, the economic and Financial /commercial agreements reversed the priorities of multinational companies in order to choose Majority ownership replaces minority ownership. At higher levels of instability of the political system, the more decisive rigidity of Financial economic agreements increases the possibility of increasing the choice of multinational companies from stocks. The rigidity of Financial economic agreements moderates the relationship between political system instability and the choice of affiliate ownership and encourages MNEs to choose majority rather than minority ownership. Finally, The multi-level nature of the environment of business economic activities shows that international multinational companies should consider different ownership arrangements under different conditions of instability of the political system, while balancing risks/risks and possible benefits. Strict economic and financial agreements are effective in providing a credible commitment against expropriation and providing a reassuring power that allows majority ownership by multinational corporations in host countries at higher levels of political system instability. Therefore, the design of a risk mitigation structure at the international level affects how firms view a potentially unstable environment at the national level. In today's competitive world, one of the ways to achieve higher economic growth is to enter global value chains, and one of the factors affecting the participation of global value chains will be the increase in the number of multilateral economic and financial treaties between countries.