Abba, the Cameroon correspondent of Nigeria-based RFI's Hausa service, was arrested on 30 July 2015 in the north of the country, where the Boko Haram armed Islamist group is active.
Fifteen months later prosecutors dropped the most serious charges of "complicity with a terrorist act" and "justifying terrorism", which can mean a death sentence.
But, despite the fact that supposedly key witnesses were never called, Abba was sentenced to 10 years in prison for "failure to denounce" terrorists and "laundering the products of terrorist acts".
His lawyers have appealed.
"RFI's management hopes that the new trial will take place as soon as possible," a statement by the channel said Sunday. "So that Ahmed Abba's case can be examined in depth and the innocence of a journalist who was only doing his job in a difficult situation may at last be established."
"Ahmed Abba does not belong behind bars, there is no case against him," Reporters Without Borders secretary general Christophe Deloire said in a statement on Saturday.
The sentence was "eminently political" and aimed to "intimidate journalists who might wish to cover the security situation in north Cameroon", the press-freedom campaign commented.
The 2014 anti-terror law, which served as a basis of the prosecution, means that "any journalist when writing just a single line for their publication writes with chills running up and down their spine", Xavier Messé of the Cameroonian paper l'Anecdote told RFI
"Ahmed Abba is not a terrorist, he's a journalist who was doing his job normally."