Output at Ku-Maloob-Zaap, Mexico's most productive oil field, climbed to a record high of 865,000 barrels per day in December, state-owned oil monopoly Petroleos Mexicanos said.

Located offshore in the Bay of Campeche, the field accounts for roughly a third of Mexico's total oil production of 2.57 million bpd.

"With a total of 170 oil-producing wells in operation, this field achieved record-high production in December of 865,000 bpd and 349 million cubic feet of gas," Pemex said in a statement Friday.

The state-owned company, which has a monopoly on crude production and distribution of petroleum products in Mexico, said Ku-Maloob-Zaap is being developed under a "rigorous" and "exemplary" management plan.

The Ku-Maloob-Zaap complex comprises heavy-crude-producing fields with the Mayan names Ku, Maloob, Zaap, Bacab and Lum and was discovered between 1980 and 1991.

Pemex ranks as the world's fifth-largest oil company by output and 13th biggest in terms of reserves. EFE