During Mexico's "Round 0" selection process, state-owned Pemex enjoyed the preferential right to designate those onshore and offshore oil fields that Pemex wished to develop. Among the blocks selected by Pemex is the ultra-deepwater Trion block, located 30 kilometers south of the maritime border between Mexico and the United States in the Gulf of Mexico and 200 kilometers east of Matamoros. Having a total area of 1,250 square kilometers and with a water depth of approximately 2,500 meters, the Trion block borders several of the deepwater blocks that will be auctioned in December 2016 as part of Mexico's Round 1 sale process.

Pemex estimates that the Trion has probable reserves of approximately 485 million barrels of oil equivalent, which is roughly equal to the total probable reserves of all other Round 1 blocks combined, and it will require upward of US$11 billion to develop.

On July 27, 2016, Pemex and the Mexican National Hydrocarbons Commission (Comisión Nacional de Hidrocarburos or "CNH") published in the Mexican Official Gazette the terms of a bid process to award to one or more private investors the right to partner with Pemex to develop the Trion block. A private investor will be the operator, and the operator must hold a working interest of between 35 percent and 45 percent of the Trion block. Pemex will be required to hold least a 45 percent working interest. The Trion block will be developed pursuant to Mexico's license contract regime.

The auction of the right to partner with Pemex in the development of the Trion block is expected to take place on December 5, 2016. Private investors wishing to participate in the auction must pre-qualify by demonstrating certain financial and technical capabilities by September 5, 2016, and the final version of the license contract and final bid terms are expected to be published on September 30, 2016.

Joint bids from multiple private investors will be permitted, provided that non-operating working interest owners may not hold more than 10 percent. The bidders must bid with a minimum carry interest of US$464 million, and the joint operating agreement will be granted to the bidder that offers the largest amount of additional minimum investment commitment.

The operators and non-operators must comply with the same minimum financial and technical requirements respectively provided for the deepwater Round 1 bidding process (CNH-R01-L04/2015).