ExxonMobil and Statoil have agreed to spend $4 billion to develop a six billion barrel oil field in the Gulf of Mexico, the two companies said. The Julia oil field, about 200 miles (320 kilometers) offshore south of New Orleans, Louisiana, will take about three years to bring into production, they said in a statement late Tuesday. The field holds about six billion barrels worth of oil and gas resources, they said. The initial six production wells will put out about 34,000 barrels a day and be tied in to the nearby Jack and St. Malo floating production facility of Chevron. Exxon and Statoil each hold a 50 percent stake in the field. Statoil\'s US-traded shares were up 1.4 percent at $23.61 in pre-market trade Wednesday, while Exxon shares added 0.1 percent to $91.23.