Moises Maionica was indicted along with four other men in December in connection with a plot that touched off corruption allegations in Argentina and diplomatic tensions between the United States, Venezuela and Argentina.

U.S. prosecutors say the five men represented the government of Venezuelan President Hugo Chavez, a persistent critic of the United States, and alleged in court that one of the defendants said the money was for the campaign of Cristina Fernandez de Kirchner, the former first lady who won Argentina's presidential election in October.

Maionica, 36, entered a not guilty plea in a Miami courtroom on January 7, but he withdrew the plea in an appearance on Friday before U.S. District Judge Joan Lenard and declared himself guilty. Sentencing was set for April 4.

Maionica's lawyer declined comment.
Three of the other suspects in the case have pleaded not guilty and a fifth remains at large. All face up to 10 years in prison and a $250,000 fine.

The case, called the "suitcase scandal" by Argentine media, erupted when Venezuelan-American businessman Guido Antonini Wilson carried the $800,000 in U.S. currency on a private jet chartered by Argentina's government to ferry officials from Caracas to Buenos Aires.

Argentine customs officers seized the cash, but Antonini was allowed to leave. Argentina is seeking his extradition from the United States to question him about possible money laundering.

Fernandez, an ally of Chavez, has called the charges "garbage," and Argentina's Congress passed a resolution condemning the United States over the investigation.

Chavez accused Washington of seeking to undermine Argentine-Venezuelan relations, while Washington says the probe launched by prosecutors in Miami is not politically motivated.

(Reporting by Tom Brown, Editing by Michael Christie)