The Mexico City-headquartered company said it lost 39.2 billion pesos ($2.98 billion) during the July to September period, compared with a year earlier profit of 24.54 billion pesos ($1.87 billion).
The company reported third-quarter revenues of 409.3 billion pesos for the quarter, near level with the same period last year.
Pemex’s crude export sales fell to 173.8 billion pesos, the company said.
For the quarter, Pemex said its tax burden was 226.1 billion pesos, marginally higher than the 223.4 billion pesos previously reported for the same period last year.
The company said that average oil production reached 2.5 million barrels per day for the quarter, a level down by a quarter compared to a 2004 peak when Pemex produced 3.4 million barrels per day.