This paper analyses the relationship between internationalization and geographic and product diversification of the Spanish exporting manufacturing firms. Using semiparametric estimation techniques to deal with no-linear dependence between the variables of interest, the results reveal that: a) there is greater combined diversification among those firms with larger export propensity; b) there is a positive correlation between geographic diversification and export propensity among firms with lower export propensity, indicating that firms adopt an strategy of minimizing risks in the international markets via geographic diversification. However, there is an industry-specific level of export propensity where the relationship disappears, suggesting a new strategy of concentration of sales in the most profitable foreign markets among firms with high export propensity.

Key words: export diversification, semi-parametric estimation, Spanish manufacturing firms.
JEL classification: C14, D21, F14.