Brazil's TAM plans to begin non-stop service between Rio de Janeiro and Montevideo from 15 November.
The Star Alliance carrier will operate daily on the route, using Airbus A320 aircraft with 144 seats in economy class and 12 in business class.
With the new service, the LATAM Airlines group will operate seven daily flights between Montevideo and three Latin American cities: Santiago, Sao Paulo and Rio de Janeiro. LAN and TAM closed on a merger earlier this year.
No carrier operates non-stop between Rio de Janeiro and Montevideo, schedules in Innovata show.
Latin American carriers have in recent months moved to launch flights or additional frequencies to Montevideo, following the July grounding of Pluna, which ran into financial problems.