Italian energy company Eni said it was cleared by Mexican authorities to start development of three oil fields in territorial waters in the Gulf of Mexico.

"Eni will now proceed with the delineation campaign of the fields by drilling four new wells, with the target of identifying a synergic and fast-track development plan," the company said in a statement.

Eni in October won all of the shares in three oil fields included under what the Mexican government categorized as Area 1 during the latest government auction.

The Italian company said the combined reserves for the three fields are approximately 800 million barrels of oil and 480 billion cubic feet of associated gas. Eni said it would move quickly on an appraisal campaign to confirm the reserve estimates.

Mexican President Enrique Peña Nieto moved last year to open Mexico up to private investors after more than 70 years under a monopoly controlled by state-run Petroleos Mexicanos, or Pemex.

Mexican Energy Secretary Joaquin Coldwell submitted a formal request to join the Western-backed International Energy Agency in October. Founded in the wake of an Arab oil embargo in the 1970s, Coldwell said joining the Paris-based IEA would advance regional interests.

Mexico is the second-largest economy in Latin America and the fourth-largest producer in the region, after the United States, Canada and Brazil, respectively.