TORONTO - Giving a convicted terrorist a 14-year prison term with seven years credit for time already served does not reflect the seriousness of the crime, the federal government said Wednesday in announcing it plans to appeal the sentence.

Saad Khalid, one of the members of the so-called Toronto 18, pleaded guilty to participating in a terror plot with the intention of causing an explosion and was sentenced in early September.

Khalid was given seven years credit for the more than three years he had spent in custody since June 2006, leaving him to serve seven more years in prison. His lawyer said Khalid could apply for parole after less than 2 1/2 years.

Ontario Superior Court Justice Bruce Durno erred by failing to order Khalid serve at least half of his sentence before being released on parole, the government said in court documents listing its grounds of appeal.

"The sentence is not proportionate to the gravity of the offence and the culpability of the offender," the Crown said in its notice of appeal filed Wednesday with the Ontario Court of Appeal.

In the summer of 2006, an intense investigation involving Canada's spy agency and the RCMP ended with the arrests of 18 people in the Toronto area and the seizure of apparent bomb-making materials. The domestic terror group was bent on detonating bombs outside the Toronto Stock Exchange and CSIS headquarters, as well as an unnamed Ontario military base.

Khalid, 23, told the court that he accepted responsibility for his role in the plot and Durno said he accepted that Khalid is truly remorseful, but added terrorist offences are "the most vile form of criminal conduct."

The Crown also alleges Durno "unduly emphasized considerations of rehabilitation and specific deterrence, and failed to adequately address considerations of denunciation and general deterrence."

Khalid's lawyer Russell Silverstein said at the time his client was "perfectly happy" with the sentence.

The Crown had called for an 18- to 20-year sentence, with five to five-and-a-half years credit for time already served.

Since Khalid's guilty plea, two others have pleaded guilty to terrorism offences and are awaiting sentencing.

Saad Gaya, 21, pleaded guilty this week to intending to cause an explosion for the benefit of a terrorist group. Last week, Ali Dirie, 26, pleaded guilty to his role in the plot.

Only one case involving the Toronto 18 has gone to trial so far, resulting in a conviction. Last September, a judge found Nishanthan Yogakrishnan guilty of participating in, and contributing to, a terrorist group.

Seven men are still awaiting trial. Seven others have had their charges dropped or stayed.