Mattarella asked Conte to remain in office to carry out day-to-day government business while the discussions continue.
Mattarella will start his meetings at 4.00 p.m. (1400 GMT) on Wednesday and wrap them up on Thursday afternoon. He is expected to see whether there is the political will to form a new government. If not, he will have to dissolve parliament, 3-1/2 years ahead of schedule, and call early elections.