TEHRAN, Young Journalists Club (YJC) - Barcelona-based La Vanguardia said Puigdemont had taken the decision in a bid to convince the government of Prime Minister Mariano Rajoy not to enforce direct rule in the region.
Puigdemont will deliver an address at 1.30 p.m (11:30 GMT), his office said.
Calling an election could either strengthen Puigdemont's mandate if pro-independence parties won, or allow him a graceful exit if they did not.
But it could also heighten divisions within the secessionist camp and bring the current campaign to a halt.
Cracks appeared late on Thursday in the secessionist coalition as members backed a vote while others said there was no alternative to independence.
An opinion poll published by the El Periodico newspaper on Sunday showed a snap election would probably have results similar to the last ballot, in 2015, when a coalition of pro-independence parties formed a minority government.