Moody's' downgrades credit rating of Brazil's state-owned oil company

Moody's Investors Service has downgraded the credit rating of Brazil's state-owned oil company due to the widening kickback-corruption scandal in which it is embroiled.

The credit rating agency announced its decision in a statement posted Thursday night on its website.

It said its downgrade of Petrobras "reflected concerns about corruption investigations and liquidity pressures that might result from delays in delivering audited financial statements."

"The ratings remain on review for further downgrade," Moody's said.

Petrobras did not immediately respond to requests for comment.

Authorities allege that top officials from Petrobras and executives from about 15 of Brazil's biggest construction firms operated a kickback scheme on contracts worth upward of $4 billion.