DUBAI, June 12 (Reuters) - Iranian state media said on Sunday that Argentinian authorities have impounded a Boeing 747 plane whose original owner, Iran's Mahan Air, was sold to a Venezuelan airline a year ago.

There was no official confirmation of the reports.

"The ownership of the aircraft was transferred a year ago and it was sold to a Venezuelan company," Mahan's spokesperson Amir Hossein Zolanvari told the official news agency IRNA. Zolanvari did not name the Venezuelan company.

It was not immediately clear if the plane was on a list of Iranian aircraft under U.S. sanctions. Mahan Air has been under U.S sanctions since 2011 for its support for Iran’s elite Revolutionary Guards.

Iran and Venezuela, which are both under U.S. sanctions, have close ties. The two countries on Saturday signed a 20-year cooperation plan.

(Reporting by Dubai Newsroom Editing by Elaine Hardcastle and Frances Kerry)