Azul recently started service on this route flying ATR-72-600's 2x/weekly (although the original announcement was for 4x/weekly).
Amaszonas Uruguay, recently formed from the leftover BQB Lineas Aereas entity, was authorized by the Argentine ANAC aviation agency in late April to fly the Montevideo (MVD) - Buenos Aires Aeroparque (AEP) route with flights expected to start in July with CRJ-200's. Amaszonas Uruguay already has one aircraft, CRJ-200LR, CX-SDU (c/n 7209), which was transferred from the parent company with two more CRJ-200's expected to arrive in July and August, respectively, and a total fleet of eight aircraft by 2018.
For full details on this new operation:
* Sky Airline - Montevideo (MVD) - Santiago (SCL) - eff 12Sep16
The Chilean "Low-Cost Carrier" is due to start daily nonstop service to Uruguay in September using A320's as part of its expansion to international destinations, such as Buenos Aires Ezeiza (EZE), Cordoba (COR) and Lima (LIM).
http://www.routesonline.com/news/38/airlineroute/267146/azul-plans-uruguay-service-from-july-2016/ via Eric Trum