Petrobras is preparing to launch a tender to build Brazil's largest-ever oil platform, according to two people with knowledge of the matter, as the state-controlled oil firm pushes ahead with ambitious plans to boost deepwater production.

Petroleo Brasileiro SA, as the Rio de Janeiro-based producer is formally known, plans to launch the leasing tender for the floating platform, known as an FPSO, by the end of August, the people said.

Equivalent vessels for deepwater production have cost between $2.5 billion and $3 billion to build. Winners build and own the platforms, and lease them to Petrobras in contracts with daily rates of up to $1 million that often last longer than 15 years.

An FPSO, or a floating production storage and offloading unit, is effectively a massive ship that is vital for deep water production in some offshore basins.

It will be the seventh FPSO in Buzios, Brazil's second most productive field and one of the biggest deepwater discoveries this century, the people said.

Petrobras is considering a unit able to process 225,000 barrels per day, more than Brazil's current largest platform, owned by Norway's Equinor ASA in its Bacalhau field, said one of the people.

The request for bids shows the state-controlled producer is moving ahead with investment plans for its most prolific fields despite the recent contraction of crude prices. The novel coronavirus pandemic has kept consumers at home and sapped demand for several fuels.

The competition for the FPSO is expected to take several months, said the people, who requested anonymity to discuss the nonpublic plans.

About 10 companies have been pre-qualified by Petrobras to compete, one of the people said, including the world's biggest FPSO lessors, Japan's Modec Inc and Amsterdam-based SBM Offshore NV.

Petrobras, Modec, and SBM declined to comment. 

(Reporting by Sabrina Valle and Gram Slattery; Editing by Richard Chang)