BQB recently announced that it would start regularly scheduled service on the Montevideo (MVD) - Buenos Aires Aeroparque (AEP) "Air Bridge" with its ATR-72-212A's on August 1 and SOL announced that it would add three more daily round-trips on the route with its Saab 340's on July 16.
After PLUNA shut down last week, BQB and SOL received authorization from the Uruguayan aviation authorities to fly between MVD-AEP on an "exceptional" or emergency basis only to be denied these rights by the Argentine aviation authorities. The Argentine ANAC instead gave "exceptional" rights to Aerolineas Argentinas, indicating that it would not grant any other carriers such rights unless Aerolineas could not accommodate all the passenger demand on the route.
The airline service agreement that Argentina and Uruguay have in place allows up to 60 "regular" flights per week by carriers from each country. This would allow Uruguay to authorize BQB (a Uruguayan airline) to fly "regular" flights between MVD and AEP but the Uruguayan government wanted to reserve that privilege for the carrier that it hopes will form to replace PLUNA using the now-defunct airline's aircraft and employees. However, there do not appear to be any private investors interested in taking over in the short run leaving the MVD-AEP "Air Bridge" seriously underserved, which is very important to Uruguay as the small country needs to be connected to Argentina for business travelers and to access the large number of airlines flying from there to the U.S., Europe, Australia, South Africa and even the Middle East.
As a result, both the Uruguayan and Argentine aviation authorities have apparently given BQB route rights between MVD and AEP and SOL, a small Argentine commuter, expanded route rights between the two cities (they already fly the route with scheduled flights on a limited basis).
Source: El Pais Uruguay 13Jul12