Following the Europeanisation studies ‘top-out’ approach in this thesis I analyse the legal approximation process with Russia as a mechanism of acquis export in the backdrop of the various European economic integration processes. At first glance approximation is a sui generis method of regional integration not fitting well in the classical economic structures, representing as a result both a challenge and an opportunity for the EU as well as important avenue for research. In order to understand and assess this method I explore the nature and objectives of approximation as a concept and as a process for law reform. I do this by differentiating it from other integration methods. I then define aapproximation as the most basic method of acquis export that employs know-how delivery and gradual adaptation as its tools for change. In order to assess its results in the Russian case I select competition law as case study for being an essential element of the market economy and a catalyst for market reform, equally serving as a pillar for economic development and stability as well as regional integration. To do this I devise a compatibility assessment formed by a comparative analysis of the fundamental areas of Competition Law; an influence analysis of the EU; and a compliance analysis of the Russian compliance with the approximation objectives. The assessment concludes that while differences in some areas remain Russia has approximated its competition law following the EU model to a high degree. This shows that, in spite of the serious political, economic and value based challenges, the objectives of this process have been met to a great degree, proving that approximation has had a major impact on Russian reform. Finally, after analysing the main obstacles and dilemmas of the approximation process I assert that any new developments of EU-Russia approximation should take into account the fact that both actors have significantly evolved as well as the interdependence of the legal, economic and political tensions between them. Ultimately, I affirm that the gradual reception of a legal model can overcome political, economic and even cultural divergence if it proves to be useful to the receiving country.