Participation in global networks and increased internationalization of R&D are important ways how Multi-National Companies (MNCs) try to diversify their knowledge and use the location-specific advantages to sustain their global competitiveness. The present Master’s thesis attempts to analyse how the Norwegian companies that are actively engaged in international operations and markets internationalize their R&D activities. The analysis of five large Norwegian companies shows that these companies increasingly diversify their knowledge base and seek complementary knowledge by engaging in international networks, especially with foreign universities and institutes. These companies also improve the mechanisms of knowledge sharing with foreign markets and international operations. International R&D strategies are often carried out in support of overall corporate business strategies and interests of these companies in the emerging markets, such as China, Brazil and India. Adapting to new international markets and partnerships and knowledge sharing are some of the main challenges in these companies.