(Changes dateline and adds details from last week's Car Wash phases)
RIO DE JANEIRO, Aug 23 (Reuters) - Brazil's federal police said on Wednesday they launched a new phase of the "Car Wash" corruption probe, targeting individuals who allegedly favored a private contractor to win business from state-run oil company Petroleo Brasileiro SA.
The police served four search warrants in two states and the federal district, a statement said. There was evidence that two individuals allegedly paid bribes to help an unnamed U.S.-based company obtain Petrobras contracts, police said.
Last week, Brazilian authorities carried out two new phases of "Car Wash," ensnaring U.S. asphalt maker Sargeant Marine, six Greek shipping companies and a former Brazilian congressman in the wide-ranging graft probe.
The phase announced Wednesday targets two lawyers who allegedly participated in the scheme, and received commissions related to the hiring of an unnamed U.S. company, according to the statement.
It is not clear if the U.S. firm implicated last week is the same as the one this week, but the police said the latest operation extends the work of recent prior phases.
The police are holding a news conference at 10 a.m. local time (1300 GMT).
Separately, late Tuesday Brazil's Supreme Court agreed to put former president and current Senator Fernando Collor on trial on corruption charges.
Collor allegedly took millions of dollars in bribes between 2010 and 2014 to help UTC Engenharia and other firms win contracts with BR Distribuidora SA, the fuel distribution unit of Petrobras, according to prosecutors.
Collor's office did not immediately respond to a request for comment.
Collor is the second former Brazilian president to face trial on corruption charges. Earlier this month former leader Luiz Inacio Lula da Silva was found guilty on graft charges. He is free, pending an appeal. (Reporting by Pedro Fonseca; Editing by W Simon and JS Benkoe)