Egypts former president
Mursi, leader of the outlawed Muslim Brotherhood, has already been sentenced in three other cases, including the death penalty for a mass jail break during the 2011 uprising against former president Hosni Mubarak and a life sentence for spying on behalf of Palestinian group Hamas.
The court on Saturday also said the death penalty had been approved for six others accused alongside Mursi, including three journalists sentenced in absentia. Two other defendants that had worked in Mursi's office were sentenced to life in prison.
The sentences are the latest in a crackdown on the Muslim Brotherhood since an army takeover stripped Mursi of power in 2013 following mass protests against his rule.
Prosecutors argued Mursi and his aides were involved in leaking sensitive documents to Qatari intelligence that exposed the location of weapons held by the Egyptian armed forces.
All of the defendants can appeal the verdicts to the Egyptian Court of Cassation, the country's highest civil court.
Relations between Qatar, a Gulf Arab state, and Egypt have been icy since July 2013 when Egypt's then-army chief Abdel Fattah al-Sisi overthrew Mursi.
Qatar had supported Mursi, who is in jail along with thousands of Brotherhood members, many of whom have been sentenced to death on separate charges.
Sisi says the Brotherhood poses a serious threat to security despite the crackdown, which has weakened what was once Egypt's most organised political group.