The 22 executives and 13 others are accused of forming a cartel and channelling kickbacks into a Petrobras scheme to pay politicians.

They were also charged with money-laundering and organised crime.

If they are convicted, the accused face more than 20 years in jail.

President Dilma Rousseff who served as chair of the Petrobras board for seven years has denied any knowledge of the corruption scheme.

"These people stole the pride of the Brazilian people," said Brazil's top prosecutor Rodrigo Janot at a press conference.

"This is the start of the investigation we have a long way to go." he said.
Brazil's prosecutor-general Rodrigo Janot attends a news conference in Curitiba December 11, 2014. Brazil's prosecutor-general Rodrigo Janot promised a "calm, balance, but firm and thorough investigation"

The executives were accused of forming a "club" to rotate contracts with Petrobras and cream off cash for politicians to look the other way.

The bribery scheme funnelled money to dozens of politicians from several parties including President Rousseff's ruling Worker's Party.

The scandal broke nine months ago after the arrest of Paulo Roberto Costa, a former Petrobras director of supplies.

Mr Costa has been giving police and prosecutors information in return for the prospects of a lower jail sentence.

Prosecutors hope to recover millions of dollars from companies involved in the bribery scheme and executives from other engineering firms could face charges.