Al Jarida Al Aoula, Al Ahdat Al Maghribia and Al Massae were sued by Gaddafi and the Libyan embassy in Morocco had asked a public prosecutor to claim damages of 30 million dirhams from each paper for articles published between 2008 and early 2009.
The Paris-based Reporters Without Borders strongly denounced the verdict, hoping it would be overturned in appeal.
It warned the three penalised newspapers faced closure because of the fines.
The trial was also strongly condemned by the National Union of the Moroccan Press, which described the trial as a "a blow for press freedom in Morocco and an attempt to execute the press".
The union staged a demonstration following the trial outside the Casablanca court.
Journalists held a banner calling for "the justice system to respect freedom of expression and stop attacks aimed at muzzling the press".