Mexico’s oil regulator said it will allow pre-qualified companies including Exxon Mobil Corp. and Chevron Corp. to bid on all 14 shallow water blocks up for auction after removing restrictions.

Companies pre-qualified to bid to explore for oil in Mexico’s shallow waters will be able to participate in auctions for all available blocks, according to Juan Carlos Zepeda, National Hydrocarbons Commissioner. Participation was limited to five blocks under prior guidelines. Companies participating in group bidding now also have the option to compete individually, Zepeda said Friday in Mexico City.

The revisions are expected to be the last ones ahead of the country’s first auction of oil blocks to private companies in the Gulf of Mexico in more than seven decades, Zepeda said. Winners of the oil blocks are expected to be announced July 15, according to the oil regulator, known as CNH.

Mexico’s state-owned oil production monopoly held by Petroleos Mexicanos came to an end last year in an effort to reverse a decade of output declines. The shallow water block auction is forecast to generate $17 billion in private investment and produce an estimated 80,000 daily crude barrels, according to Mexico’s energy ministry.

Nineteen individual companies and seven groups pre-qualified this week to bid on the blocks.