RIO DE JANEIRO (Dow Jones)--Brazilian state-run energy giant Petroleo Brasileiro (PBR, PETR4.BR), or Petrobras, expects to sign contracts to complete eight floating offshore oil platforms in the first half of 2012 as it ramps up efforts to develop recently discovered deep-water fields, the company said Tuesday.  Petrobras will receive proposals Tuesday for building and integrating the processing modules for the eight floating production, storage and offloading vessels, known as FPSOs, that will be installed at fields in the BM-S-9 and BM-S-11 blocks in Brazil's Santos Basin, Petrobras said in an email. That's where a cluster of oil discoveries were made that have been estimated to hold 50 billion barrels of crude.

" At this time, only technical and commercial proposals will be received," Petrobras said. Each proposal will remain in a sealed envelope until it is studied by a commission established to evaluate the proposals, the company added. " The respective contracts will be signed yet during the first half [of 2012]."

The federal oil company said that it wouldn't comment further until the tender process is complete and the contracts are signed.  Petrobras is overseeing the tender process on behalf of its partners in the two blocks, including BG Group (BRGYY, BG.LN), Galp Energia (GALP.LB) and Repsol Sinopec. The value of the FPSO tender has been estimated at between $5 billion and $7 billion.  The eight FPSOs are clones, numbered P-66 to P-73, with the hulls under construction at a shipyard in Rio Grande do Sul state. The first platform, P-66, is expected to be completed by November 2013.

-By Jeff Fick, Dow Jones Newswires 55-21-2586-6085 jeff.fick@dowjones.com