UPDATE 3-Brazil's Petrobras says to sell dollar bonds

* Company to tap capital markets, 3rd time this year

* Multi-tranche issue will help pay off bridge loan

* Petrobras aims to diversify funding sources with bond (Recasts with Petrobras confirmation)

SAO PAULO, Oct 19 - Brazil's state oil company Petrobras plans to sell U.S. dollar-denominated global bonds in different tranches in efforts to exchange bridge loans for long-term debt, the company on Monday.

Petrobras, which tapped international capital markets twice earlier this year to pay off a bridge loan, did not specify the issue amount or the maturities.

It said it hired hired Citi, HSBC, JP Morgan and Santander as lead managers for the operation.

The company is seeking to structure the deal so that investors can choose from a variety of maturities and amounts, a source with first-hand knowledge of the transaction told Reuters earlier.

"The novelty here is that this issue will be a multi-tranched issue, that is, it should have more than one maturity," the source said. "Therefore, with this structure they should be able to grab a bigger volume."

Petrobras is expected to offer bonds with 10- and 30-year maturities, according to International Financing Review, a Thomson Reuters publication.

IFR said the company will start a roadshow for investors on Tuesday in San Francisco. Other stops include London and Los Angeles on Wednesday, and Boston and New York on Thursday.

By tapping debt markets abroad, the company may decrease its reliance on state funds to finance its $174.4 billion five-year investment plan. Less than a third of the more than $30 billion that Petrobras has raised this year has come from private investors.

In addition to this year's $6.5 billion bridge loan led by Banco Santander and Societe Generale, Petrobras secured a $12.5 billion credit line from state development bank BNDES, $2 billion in loans from the EximBank of the United States and $10 billion from the China Development Bank.

The yield on the 7.875 percent bond due in March 2019 US71645WAN11=ITAU jumped 12 basis points to a one-week-high of 5.56 percent on Monday from 5.44 percent on Oct. 16.