The internationalization of business activities creates for companies the option of operating in various foreign markets for the sake of their development, profit and growth. Thus, the very internationalization of business activities of companies represents the survival of small companies and large companies in the world and in Croatia as well, and all this is due to increasingly strong competition in an increasing number of markets.The thesis thoroughly deals with clarifying different company status changes, namely company acquisitionsand mergers in the Republic of Croatia. Further more, the dissertation precisely explains the business process during acquisitions of joint-stock companiesand limited liability companies, as well as the methods of acquisition combination of joint-stock companies and limitedliability ones. Acquiring companies take over and continue business activities based on the acquired assets of the companies they have taken over. It also represents the external basic form of company growth, and they also have numerous similarities as a reason for acquisition or merger, impact on employees and others. Ownership acquisition is the takeover of a company by purchasing the majority of shares with voting rights.Also, the paper explains how mergers combine two business entities into one and the possible merging combinationsof companies formed into a completely new, third entity. Certainly, there are key differences between the “acquisition" and “merger” hence their corporate similarities as well as opposites are mentioned in the company status changes throughout the thesis. In recent years, the number of mergers and acquisitions of companies has significantly decreased, which showed the value of the transactions, that in 2018 a total of 560 million euros were realized, while in 2015, 1.07 billion euros were realized, which is a difference of almost half a million euros.The INA and MOL example is as interesting as educational for this subject to determine what legal acts are to be used and which are not legally appropriate during an acquisition.The acquisition of INA by the Hungarian MOL is considered unsuccessful due to non-compliance with the rules in the acquisition process. It also gives a great insight what is to happen when certain acts and laws are violated especially if there is a present involvement of the Government.The paper details the entire process of the event from cause to effect. The main goal of this work is to support the theory with a strong, worthy example that shows oversights in implementing thecompany status change and to provide the reasoning why obeying the given rules and laws is so important for the business process.