Country could see weeks of gridlock and even fresh elections.
Politicians and investors are bracing for a revival of Europe's fiscal and currency crisis and a deepening of euro-scepticism as Italy grapples with forging a stable government after two-day general elections.
After a poll whose low turnout marked voter discontent with a chaotic political system, a centre-left coalition looks poised to take the Lower House of Parliament, while a right-wing party led by former Premier Silvio Berlusconi may take a slender majority in the Senate Upper House.
A third party, the Five Star Movement, led by a comedian turned damn-them-all activist, Beppe Grillo, has grabbed third place, while outgoing Prime Minister Mario Monti's party has trailed a distant fourth.
If these trends are confirmed officially, Italy could be in for weeks of gridlock, possibly culminating in fresh elections, say analysts.
"They just see the austerity, they don't see the benefits of keeping the interest rates down," Jeffrey Bergstrand, a professor of finance at the University of Notre Dame in Indiana, told Reuters.