International road transportation service between Chile and Argentina, Bolivia, Brazil, Paraguay, Peru or Uruguay is reserved to companies majority-owned and controlled by nationals of those countries. 
"Article 2.- The international transport of passengers or cargo may only be carried out by authorized companies, under the terms of this Agreement and its Annexes.
[...]
Article 22.-
1. The signatory countries will only grant original permits to companies incorporated in accordance with their own legislation and with real domicile in their territory.[...]
3. More than half of the capital stock and effective control of the company will be in the hands of natural or naturalized citizens of the signatory country that grants the original permit.[...]" (Decree 257 adopting the International Road Transportation Agreement signed by Argentina, Brazil, Bolivia, Paraguay, Peru, Uruguay and Chile (17 October 1991), Articles 2 and 22)
Decree 257 adopting the International Road Transportation Agreement signed by Argentina, Brazil, Bolivia, Paraguay, Peru, Uruguay and Chile (17 October 1991), Articles 2 and 22
[<a href="https://www.bcn.cl/leychile/navegar?idNorma=11600">Decree</a>]