Prosecutors say al-Attar confessed to taking payment from Israel to spy on Egyptians and Arabs in Turkey and Canada, using his position in the bank to obtain information on specific accounts.
Al-Attar was also expected to approach potential recruits, according to prosecutors, who said he was paid $56,000 before he was arrested.
Ibrahim el-Basyuni, al-Attar's defence lawyer, has said his client's confession was made under duress.
The defendant told the court in an earlier session he confessed because he was tortured with electric shocks during interrogation.
Al-Attar's alleged confession claimed he fled Egypt in 2001 after he was sentenced to three years in prison for issuing a bad money order, and that he later sought asylum with the UN refugee agency in Turkey.
The confession also alleged al-Attar converted to Christianity in Istanbul before being sent to Canada, where he delivered spy reports about Christian Egyptians.
Hani Hamoodah, prosecuting, insisted the defendant made the confession freely and without coercion.
The three Israelis convicted in absentia in the case, said to be Mossad agents, were each sentenced to 15 years in jail.
Israel has dismissed the case as a fabrication.
In 1996, Egypt detained Azzam Azzam, an Israeli Arab textile worker, and sentenced him to 15 years in prison for spying for Israel.
Egypt said Azzam passed messages in women's underwear using invisible ink.
Both Azzam and Israel denied the charges. He was released after serving eight years as part of a deal that included the release of six Egyptian students in Israel.