Monti, who stepped down after the Italian parliament voted 373-67 in favor of the 2013 national budget, had previously said he would resign once the budget was passed.
However, he could announce his candidacy for the February elections when he holds his final news conference Sunday, Italy's ANSA news agency said.
Some political watchers in Italy consider Monti's announcement a mere formality.
"He is de facto a candidate," said Stefano Folli, a columnist for the business daily Il Sole 24 Ore. "He is the head politician of this coalition."
Monti has become a centrist rallying point for a political coalition between former Prime Minister Silvio Berlusconi and the left-center Democratic Party led by poll front-runner Pier Luigi Bersani, The New York Times said.
Monti's own popularity has waned while he was in office. An economist by training, Monti has proposed raising taxes and cutting spending.
He is likely to remain in office in a caretaker role with the power to handle emergency legislation until a new government is formed, the Times said.
"He's already a senator for life, so he doesn't have to become a candidate in the technical way," Folli said.