A second reason why internationally produced films tend to dominate the domestic market is financial.

Internationally produced films tend to dominate the domestic market. The reason for this is financial. 
= The reason they tend to dominate is financial. 
= The reason they tend to dominate the domestic market is financial.


Internationally produced films tend to dominate the domestic market for financial reasons. 

Internationally produced films tend to dominate the domestic market because of financial reasons.