"Taking into account the efficiency, demand and costs of the route, the airline is making this adjustment to boost the capacity and profitability of the flights," it noted in a statement.
TAM explained that passengers can still travel to Britain using its daily flight from Sao Paulo, Brazil's economic capital
TAM, which merged with Chile's LAN airline in 2012, had three weekly Rio-London flights. Last August, it cancelled its direct Rio-Paris and Rio-Frankfurt flights.
But the Brazilian airline said it was maintaining its direct international flights from Rio bound for Buenos Aires, Miami and New York.
But those flights will be terminated on July 19.