Estrada has promised not to seek public office again, Voice of America reported. The government also has a policy of pardoning convicts who are over age 70.
The pardon was controversial. Estrada was convicted after a six-year trial, of making millions of dollars from illegal gambling and sale of shares in government pension funds.
Another former president, Fidel Ramos, urged Macapagal-Arroyo to be cautious.
"It would be a terrible calamity to the great, great, great majority of the Filipino people who suffered from the plunder that has been proven in court after due trial, beyond reasonable doubt," said Ramos. "She must consider and weigh very carefully what ordinary people might do. What the victims of the so-called plunder might do."
Macapagal-Arroyo served as Estrada's vice president when the former actor was elected president in 1998 and replaced him when he was ousted three years later.