In this paper, we aim to extend the internalization theory by Buckley and Casson [Buckley, P.J., Casson, M., 1976. The Future of Multinational Enterprise. Holmes & Meier, New York] and Caves [Caves, R.E., 1971. International corporations: the industrial economics of foreign investment. Economica 38, 1-27] in two respects. First, we hypothesize that synergies arising from a technology-oriented cross-border M&A increase the stock market value of an acquirer's R&D spending. Second, we hypothesize that an acquirer's access to a country with more favorable R&D environment through the target firm is the main source of synergy arising from intangibles in these M&As. Our empirical results of analyzing data from 10 most R&D active countries in Europe are consistent with these hypotheses and support our extension of the internalization theory. Specifically, we find that multinationality of a firm with intangible assets as such does not add value to R&D, but the combination of its own R&D with that of a firm located in a country with highly favorable R&D environment.