Party autonomy with effect against third parties as a means of harmonizing and unifying regulation of transfer of ownership in the private international law

The absence of an effective solution of ownership of movable property in cross-border transactions underscores the relevance of this article. The traditional lex rei sitae connecting factor fails to address issues in cases of mobile conflicts. Party autonomy presents a potential tool to overcome this challenge. However, the primary obstacle to its widespread acceptance is the possible adverse impact of parties’ agreements on the rights of third parties. This article aims to assess the potential application of party autonomy as a means to harmonize and unify the regulation of the transfer of ownership of movables, and to justify the effect of the parties’ chosen legal order on the third-party right. The research employs general scientific methods, including analysis, synthesis, deduction, induction, and dialectics, alongside specific legal methods such as dogmatic and comparative analysis. The study concludes that the party autonomy can serve as an effective instrument for harmonizing and unifying regulations governing the transfer of ownership of movables while adequately protecting third-party rights. Third parties are provided with special mechanisms to safeguard their interests. Within the framework of unification, for certain categories of movables, registration systems may offer a means to ensure protection of third-party rights. Consequently, both harmonization and unification prove to be effective regulatory tools for the transfer of ownership of movables. Finally, the article proposes directions for further research, focusing on determining the optimal balance between harmonization and unification in regulating the transfer of ownership through party autonomy, taking into account the advantages and disadvantages of each approach.