Argentina's Supreme Court has ruled that a media bill passed in 2009 is constitutional thus clearing the way for the break-up of large media groups.

Court judges ruled that the law had no unconstitutional elements, "It is legitimate that a law sets general limits a priori, because this way it favours freedom of expression and prevents the concentration of the market," they concluded.

According to source, the country's biggest broadcasting and newspaper company, Clarin, had appealed against the law proposed by President Cristina Fernandez de Kirchner.

Critics say the bill is an attempt to silence opposition voices in Argentina while supporters say it will boost pluralism and reduce the dominance of big corporate interests.

Clarin has been involved in an open dispute against Cristina Fernandez de Kirchner's government since 2008.

The 2009 law stipulates that any one owner can hold a maximum of 24 audiovisual licenses.

It also bans TV networks from amassing more than 35% of the nation's viewers, and subjects the sale of broadcast licenses to government approval.

The Clarin group will be especially affected by a clause which bans ownership of more than one free-to-air and one cable TV stations and more than one radio station in the same city and with its massive presence in the capital Buenos Aires, it is expected to be forced to shed control over many stations.