Chavez says RCTV, the country's oldest private broadcaster, supported a bungled coup against him in 2002. He has had a long-running battle with opposition television stations, calling them "horsemen of the apocalypse."

"Let us defend democracy, let us defend freedom, let us defend free independent media such as RCTV," RCTV's managing director, Marcel Garnier, told demonstrators in Caracas.

"Or we will allow the president to topple the country over the precipice of totalitarianism where not even his own supporters can express their opinions," he said as the crowd waved flags, applauded and blew whistles.

Chavez has vowed not to renew RCTV's broadcast license when it expires on May 27. It will be replaced by a state channel showing programs that promote the values of Chavez's self-styled leftist revolution. He accuses RCTV's saucy soap operas of spreading immorality.

Analysts have identified a critical media as one of the principal safeguards against the president building a Cuban-style state in the OPEC nation.

Chavez, re-elected by a landslide last year, still enjoys support of about 60 percent of the public on the back of massive social spending. But a leading pollster has also found a majority of Venezuelans oppose the closure of RCTV.

BELOVED SOAP OPERAS

Datanalisis found almost 70 percent of Venezuelans would rather RCTV kept broadcasting, but worried more about the loss of their favorite soap operas than free speech.

RCTV has been showing a nostalgic collection of clips from comedies, soap operas and Christmas specials that have been part of life in the Caribbean country since it started transmission in 1953.

"It is like losing a close relative," said Renaldo Gonzalez, a student at the protest, whose family members have worked at RCTV as actors, producers and directors.

During the 2002 coup against Chavez, which was led by business and military leaders, opposition channels showed cartoons and films while massive crowds of Chavez's supporters mobilized for a counterattack.

Since then, Chavez has accused private television channels of manipulating the news.

But on Saturday, while opposition channel Globovision showed tens of thousands of protesters swelling the streets, Venezuelan state television showed empty roads and groups of five or 10 protesters walking to the march.

Housewife Maria Tintero said she was marching to support RCTV because "it tells the truth. The state channels never say what is going on in the country, about how much insecurity and poverty there is."

She disagreed that it was fair to shut a channel that supported a coup against an elected leader.

"The first coup, that was Chavez," she said, referring to the president's unsuccessful coup attempt in 1992.

Granier told the crowd that the loss of RCTV could foreshadow a dangerous reversal of Latin American democracy.

"The president has to choose between the democratic path Venezuelans want, or he can follow the terrible path where Fidel Castro, Adolf Hitler and Joseph Stalin showed the way," he said.