An Egyptian court has set January 1 as the appeal date for Australian journalist Peter Greste and two of his Al Jazeera colleagues, jailed in the country since December 2013.

Greste was sentenced to seven years' jail in June after being convicted of aiding a terrorist organisation.

The verdict was widely condemned internationally, and Egypt's president Abdel Fattah al-Sisi had since made sympathetic remarks about the three imprisoned journalists, saying he wished they had been deported and not put on trial.

Mr Sisi had not suggested he would use his presidential power to pardon the journalists.

The Al Jazeera television network's Qatari owners back the Egyptian religious and political organisation Muslim Brotherhood, which was declared a terrorist organisation by the Egyptian government last year.

The network had been at odds with Egypt's leadership since Islamist president Mohammed Morsi was ousted in July 2013; Mr Sisi took office in June this year after a period of instability.

Greste and his colleagues Canadian-Egyptian national Mohamed Fahmy and Egyptian national Baher Mohamed all denied charges of working with the Muslim Brotherhood.

Eleven other defendants tried in absentia, including one Dutch and two British journalists, were given 10-year sentences.

Egypt's court of cassation will examine the Greste appeal.

"The court of cassation can order a retrial or even reject the appeal," defence lawyer Negad Borai said.

Egyptian and international human rights groups held up the trial and conviction of the journalists as an example of the "broken" Egyptian judicial system.

Al Jazeera said, in a statement, the appeals hearing "will look at the process behind the original trial, a process that Al Jazeera says was flawed".

The network planned to mark 300 days since the arrest of its journalists this Friday with "300 seconds of silence on-air, accompanied by images of the detainees and the campaign to release them".

Reuters/AFP