Mexico's government is offering its first deep-water oil and gas exploration blocks to bidders as part of the historic energy industry overhaul that opened the sector to private investment.

The secretary of energy says 10 blocks will go up for bid in September 2016, four of them in the "Lost Belt" in the Gulf of Mexico maritime boundary between Mexico and the U.S. A Thursday statement says the auction was set for late next year to give multinational companies time to analyze the projects.

So far, Mexico has awarded contracts for exploration and production on land and in shallow water since the 2014 reform that ended seven decades of state monopoly on the oil business.

Mexico produces 2.2 million barrels a day, down from a 3.4 million peak in 2004.