International oil companies are reaching out to Brazil after it opened its most promising offshore region to increased competition, a move welcomed by Petrobras Chief Executive Officer Pedro Parente as he seeks partners to spread investment costs.

Producers rushed to contact Houston-based Brazilian officials last week after Congress removed a requirement that Petrobras control operations at all new projects in an area known as the pre-salt, Parente said. It’s the most investor-friendly change in regulation since the 1997 oil law that ended the company’s monopoly in Brazil.

“Our foreign ministry representation unit in Houston, in the very following day, received seven manifestations of interest of big companies," Parente said at Bloomberg’s offices in New York City.

The policy shift comes as the state-controlled producer is selling assets to slash debt, which stood at $125 billion in the second quarter. The Rio de Janeiro-based producer has a group of more than 30 projects worth about $40 billion that it is marketing to potential buyers, Parente said.

Allowing others to control drilling and production in the potentially oil-rich pre-salt will provide a larger group of offshore operators for Petrobras to team up with at upcoming licensing rounds. Foreign oil companies haven’t had a chance to bid for licenses to operate in the pre-salt since before anyone knew how vast the reserves were.

The nationalistic oil policies were put in place in 2010 when the government moved to put Petrobras in control of the biggest group of offshore discoveries this century. This limited access to bidding with Petrobras as a minority partner, or trying to buy into an existing license awarded under previous rules.

Pre-salt oil was formed when the South American and African continents began separating more the 100 million years ago. The repeated flooding and evaporation of salt water in what is now the South Atlantic created a layer of the mineral as thick as 2,000 meters that blankets the deposits. The biggest discovery in the area, Libra, holds an estimated 8 to 12 billion barrels of recoverable reserves.

Interest in the region is strong. Petroleo Brasileiro SA, as it is formally known, recently sold its stake in a pre-salt concession to Statoil ASA for $2.5 billion. The government is planning to offer new pre-salt exploration acreage in 2017, and the new rules let Petrobras bid more selectively as it looks to contain capital expenditures. The company is likely to continue shedding staff in the next two years, said Parente.

Higher-than-expected output at the pre-salt has cut Petrobras’s break-even cost to $40 a barrel, and the company can lower it further, said Parente. The company will continue efforts to reduce spending even if oil prices rebound, he said, adding that he sees oil at $50 to $55 a barrel next year.

“Productivity of the pre-salt fields in Brazil is amazing,” said Parente. “Some wells produce 40,000, 50,000 barrels a day per well. So I think this is what is in the mind of these companies.”

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Petrobras is also looking to bring in partners for its refineries, which posted losses in four out of the past five years. The "ideal" partner would supply knowledge, not just money, according to Parente.

The influx of partners, asset sales and increased competition in offshore fields from foreign producers will force Petrobras to become more efficient, the company’s top managers said.

“Five to ten years from now the market landscape will be completely different,” said Nelson Silva, Petrobras’ head of strategy who was at the interview. “It will put pressure in us to improve.”