(Adds Petrobras comment)
By Jeb Blount and Marta Nogueira
RIO DE JANEIRO, Aug 4 (Reuters) - The first oil output from a long-duration test in Brazil's giant Libra offshore area will flow in the first quarter of 2017, platform joint operator Odebrecht Oil & Gas (OOG) said on Tuesday.
That is later than the 2016 second-half start forecast in June by Brazil's state-run oil company Petroleo Brasileiro SA , or Petrobras, which manages exploration in Libra.
A Petrobras-led consortium won exploration and production rights to Libra, one of the world's largest recent oil discoveries, in 2013. Total SA and Royal Dutch Shell Plc are also parts of the group, with 20 percent each, while Chinese state oil companies CNOOC Ltd and China National Petroleum Co got 10 percent each.
"The test will begin in the first quarter of 2017," Rogério Ibrahim, chief financial officer of the 84 percent-owned unit of engineering group Odebrecht, said in an interview.
"We deliver the ship at the end of December (2016) and the receivables start flowing (to us) in 2017."
The later startup date is one of the first signs Petrobras may be struggling to meet even the scaled-back targets in its $130 billion 2015-2019 strategic plan presented in June.
Investor presentations on that plan included a second-half 2016 Libra test start-up. On Tuesday, Petrobras said it "will only confirm that the delivery of the production ship is planned for the fourth quarter 2016."
The new strategic plan cut spending 40 percent from the previous version, citing falling world oil prices and Petrobras' soaring debt. The plan was aimed at calming investor worries about a massive corruption scandal that has ensnared Petrobras and Odebrecht.
Libra, which contains an estimated 8 billion to 12 billion barrels of recoverable oil and equivalent natural gas, enough to supply all U.S. needs for one to two years, is at the center of that plan.
A 50-50 partnership between the Odebrecht unit and Teekay Offshore Partners LP will operate the oil production vessel, a converted oil tanker known as a floating, production, storage and offloading ship, for Petrobras on a 12-year lease.
Ibrahim said on Tuesday the partnership will receive an $804 million, 10-year secured loan, to finance 80 percent of the ship's cost. Loan payments will begin with the Libra test in 2017.
The vessel, designed to process 50,000 barrels of oil and 4 million cubic meters (141.3 million cubic feet) of natural gas a day, will be built at the Jurong shipyard in Singapore. (Reporting by Jeb Blount; Editing by Jonathan Oatis and Richard Chang)