Ihsane El Kadi, director of Radio M and news website Maghreb Emergent, was found guilty of "publishing false information likely to damage national unity" and "reopening the issue of the national tragedy," Algerian media reported.
El Kadi was also fined 50,000 dinars (322 euros), Algerian League for the Defence of Human Rights vice president Said Salhi told AFP.
He remains at liberty as the court in Algiers did not issue a warrant for his arrest, Salhi added.
El Kadi was found guilty of "publishing false information likely to damage national unity" and "reopening the issue of the national tragedy," Algerian media reported.
He was prosecuted following a complaint from the then communications minister Amar Belhimer over an article he published on the banned Islamist movement Rachad and the pro-democracy protests that have swept Algeria in recent years.
A Charter for Peace and National Reconciliation adopted in 2005 made it an offence punishable by up to five years in prison to discuss Algeria's "black decade", the conflict between the army and armed Islamist groups that devastated the country between 1992 and 2002.