UPDATE 1-Former Petrobras executive charged, said to favor Vantage Drilling
(Adds details throughout, efforts to reach companies for comment, previous comment from Zelada's lawyer, link to timeline)
SAO PAULO Aug 6 (Reuters) - Brazilian prosecutors on Thursday presented formal charges against Jorge Zelada, the former head of state-run oil firm Petrobras' international division, and five others, saying they favored U.S. company Vantage Drilling in a rig contract.
The most recent charges presented in Brazil's largest-ever corruption scandal included money laundering and corruption, and Zelada will stand trial with dozens of other engineering tycoons and former Petrobras executives if a judge accepts them.
One of the six charged by the prosecutor was Hsin Chi Su, chief executive of Taiwanese shipping firm TMT.
The federal prosecutor's office in the southern city of Curitiba said in a statement that Su and the others paid bribes of $31 million to Zelada, other ex-Petrobras officials, and Brazil's PMBD political party.
The PMDB, or Brazil Democratic Movement Party, is part of President Dilma Rousseff's governing coalition.
The prosecutor's office said that in exchange, Petrobras officials improperly favored Vantage Drilling for a contract with the oil company for the use of its Titanium Explorer rig. The award of the contract was rife with irregularities, prosecutors said.
Vantage Drilling did not answer calls for comment by Reuters to its executive office in Houston. Representatives of TMT could not be reached.
Vantage Drilling's CEO said on July 2, when Zelada was arrested and prosecutors first mentioned the company, that they had no evidence substantiating allegations of improper activity in connection with the awarding of the Titanium Explorer contract. Continuación...