CARACAS -(Dow Jones)- Venezuelan intelligence agents raided Tuesday the offices of Industrias Venoco CA, a petrochemicals and lubricant company linked to Franklin Duran, who was convicted for plotting to cover up alleged illegal campaign contributions by President Hugo Chavez to Argentina's President Cristina Kirchner.

Government and military intelligence agents searched documents in the offices of Venoco across the nation as part of an investigation into money laundering by the company, the prosecutor's office said in an emailed statement. Calls to the company were not returned.

On Saturday, Chavez threatened to expropriate Venoco, saying that its owners, Duran and Carlos Kauffman, who pleaded guilty and testified in a U.S. federal court that the Venezuelan government used them to hush a political scandal arising from the alleged illegal campaign contributions, "were lending themselves for actions in the United States against the homeland."

U.S. federal jurors on Monday found Duran guilty of acting as an unregistered foreign government agent in the U.S., where U.S. prosecutors said he tried to persuade Guido Alejandro Antonini Wilson to cover up the source of the $800,000 in cash that he was caught carrying in a suitcase in a private plane arriving in Buenos Aires in 2007.

U.S. prosecutors said the money was destined for Kirchner's election campaign.

Venezuelan Foreign Minister Nicolas Maduro said in a statement Tuesday that Duran's conviction was part of an intelligence operation by the U.S. government to attack the Chavez administration.

-By Darcy Crowe, Dow Jones Newswires; (58) 212 905 6304; darcy.crowe@ dowjones.com