Argentine political analyst Graciela Romer said the bill's passage would bring limited political benefit for the President. Her approval ratings are below 30 percent, hit by her combative style, a lengthy standoff with farmers over export taxes, and a slowing economy.

"This is a government with serious problems of public support," she said. "This issue is not a priority right now for Argentines who are more worried about unemployment, rising crime and inflation."

Fernandez, who lost her congressional majority in June legislative elections, pushed to get the bill passed before new lawmakers are seated in December.

It sets limits on the number of media outlets companies can own, forcing some to sell off their holdings within a year, which would occur in the run-up to a 2011 presidential election.

It also calls for a new government-controlled regulatory body responsible for handing out and renewing radio and TV licenses.