The Latin Grammy music awards organization also supported Alejandro Sanz, one of Latin America's most popular singers, saying the cancellation of the concert planned for Thursday smacked of censorship.

Actress and singer Jennifer Lopez, music's Ricky Martin and Hollywood star Penelope Cruz also signed the letter protesting Venezuela's decision.

"Because we believe in a Latin America where we should be free to express our opinions ... we hope in our hearts that this problem is resolved," the letter, released by Sanz's publicity office, said.

In 2004, Sanz accused Chavez of trying to stymie a nationwide campaign for a recall referendum against the president. Millions of Venezuelans signed a petition that year seeking such a vote, but Chavez eventually won the referendum easily.

Last year, government officials banned a Sanz concert after saying the venue, a state-run stadium, was an inappropriate place to host a Chavez critic. The concert plan was resurrected, only to be canceled again this month by its promoters, who gave no reason for the decision.

Chavez and his aides routinely brand local detractors as traitors and foreign critics as part of a U.S. plot to destabilize his self-styled socialist revolution.

The anti-U.S. president closed a critical TV station last year. But other channels -- with albeit much lower ratings -- vehemently oppose him and many Venezuelan newspapers are openly critical of his government.

(Reporting by Fabian Cambero; Writing by Saul Hudson, editing by Patricia Zengerle)