Brazil will resume auctions of oil rights in the first half of 2015 after a nearly two-year lapse, the head of the ANP regulatory agency said here Monday.Magda Chambriard announced the 13th round of auctions during the opening of the Rio Oil and Gas conference.

While the ANP has yet to decide exactly which fields will be up for bids, the auction will include sites from the northeastern State of Rio Grande do Norte to Rio Grande do Sul in the far south, she said.

Chambriard did not say whether the auction will include the pre-salt region, so-named because its reserves are located under water, rocks and a shifting layer of salt at depths of up to 7,000 meters (22,950 feet) below the surface of the Atlantic.

That region, the main focus of investment by state-controlled oil giant Petrobras, could vastly increase Brazil's proved reserves and turn the country into a major crude exporter.

The pre-salt area is governed by a special regulatory regime that allows only for production-sharing contracts, not outright concessions.

Brazil held regular auctions of oil rights from 1999-2008 under traditional terms for concessions, but suspended the sales pending adoption of new regulatory framework for the pre-salt deposits.

In 2013 there were two auctions of concessions and Brazil's first under a production-sharing regime.