The province has agreed with the petroleum company, the former Statoil, to acquire a 10 percent share in the planned exploration of the oil field in the Bay du Nord, 500 kilometers (300 miles) northeast of capital city Saint John's, said Dwight Ball, premier of Newfoundland and Labrador Province.
The field is estimated to contain at least 300 million barrels of oil, lying some 1,200 meters (3,900 feet) below the ocean's surface. Plans call for the first deep-water platform in eastern Canada, officials said.
Exploratory work is set to begin in 2020, with the first oil production expected in 2025.
"This framework agreement provides important clarity and stability (for) Equinor and our partner Husky Energy," said Unni Fjær, vice president of Equinor's Canadian subsidiary.
According to official estimates, the Bay du Nord project will cost Can$6.8 billion ($5.2 billion) while generating some Can$3.5 billion in revenues for Newfoundland, through taxes and royalties.
Statoil, Equinor's predecessor, had announced in 2013 the discovery of oil in the Flemish Pass Basin, a relatively little-explored geological formation within the Bay du Nord.
Three years later the Norwegian company announced that the oil field contained exploitable reserves totalling between 300 million and 600 million barrels.