Mexican crude production came in at an average of 2.52 million barrels per day in the first eight months of 2013, down 0.78 percent from the same period of last year, state oil monopoly Petroleos Mexicanos said.

Average oil output in August totaled 2.51 million barrels per day, 1.3 percent more than in July, Pemex said in a statement.

Of the total produced in August, 55 percent was heavy crude, 33 percent was light crude and 12 percent was very high quality super-light crude, the company added.

Three-fourths of the crude output was extracted from offshore fields in the Gulf of Mexico, while 19 percent corresponded to the southern onshore region and 6 percent to the country's north region.

Between January and August, Pemex exported a daily average of 1.17 million barrels to its clients in the Americas, Europe and the Far East, earning $26.7 billion in revenue from those sales.

Mexico's Congress is currently debating an energy overhaul bill that would allow private domestic and foreign oil companies to enter into profit-sharing joint ventures with Pemex, which was created when the country's oil industry was nationalized in 1938.

The aim of the overhaul plan is to boost production to 3 million barrels per day by 2018 and 3.5 million bpd by 2025 by attracting the private capital needed to develop promising deep-water fields in the Gulf of Mexico and onshore shale deposits.

Pemex achieved its highest level of oil output in 2004 - 3.38 million bpd - but production subsequently fell over the next seven years due to aging fields and a lack of major new discoveries.

The company, which has a monopoly on crude exploration and production and distribution of petroleum products in Mexico, ended 2012 with average daily oil output of 2.55 million barrels and average daily exports of 1.26 million barrels. EFE