In a widening corruption probe into Venezuela's state oil company by United States, Swiss regulators have agreed to provide U.S. prosecutors with records from at least 18 banks relating to the oil firm.

The requests for information from two separate U.S. authorities were part of their investigations into alleged money laundering and corruption in connection with the conclusion of energy contracts with Petroleos de Venezuela SA (PDVSA), Switzerland's Federal Office of Justice (FOJ) said on Friday.

U.S. authorities say they have traced over $1 billion to a conspiracy involving a Venezuelan magnate who allegedly paid bribes to obtain contracts from PDVSA. They are separately investing representatives of Venezuelan energy company Derwick Associates, which has done business with PDVSA, based on the FOJ's statements.