Mexico produced 2.482 million barrels per day (bpd) of crude oil in July, the lowest monthly output in nearly 18 years, state-run oil monopoly Pemex said on Friday.

President Enrique Pena Nieto is seeking to push a bill through Congress to increase private investment in the oil industry in the world's 10th-biggest crude oil producer.

The July production figures were the lowest since October 1995, according to Energy Ministry data.

Mexico has seen output drop by a quarter since hitting a peak of 3.4 million bpd in 2004.

In September, Congress will formally begin debate over Pena Nieto's reform plan, which aims to create a new profit-sharing contracting scheme to lure oil companies back to Mexico, where the oil and gas industry was nationalized in 1938.

The government hopes fresh investment will help Mexico exploit deep-water fields and shale deposits, areas where it lacks expertise. If Mexico cannot step up production, it risks becoming a net energy importer this decade, the government says.

The latest Pemex data showed Mexico exported 1.210 million bpd in July, up 11 percent compared with the previous month. Still, exports are down nearly 40 percent since 2004.

Two-thirds of Mexico's oil fields are in decline. Pemex estimates that oil output at the country's top producing field, Ku Maloob Zaap, will drop 60 percent over the next decade.