Wasat Party deputy leader Essam Sultan has been fined LE40,000 and ordered to pay damages of LE30,000 for insulting Mubarak-era prime minister Ahmed Shafiq, judicial sources said on Tuesday.
Sultan was convicted in three separate cases of insulting Shafiq, who came second to Mohamed Morsi in last year's presidential election runoff, and levelling "baseless" graft and corruption accusations against him in TV and press comments.
Sultan, along with Islamist Wasat Party leader Aboul Ela Madi, was arrested in late July, weeks after Morsi's removal on 3 July.
He is standing trial on separate charges including incitement of violence and murder, and "insulting the judiciary."
A wave of detentions has rocked the Muslim Brotherhood and its Islamist allies. Dozens of the group's senior leaders, along with hundreds of other Islamists, have been rounded up since Morsi's ouster.
In early September, Ahmed Shafiq refused to rule out running for president again if people "insist and commission" him for the post.