ROME — Italian voters delivered a rousing antiausterity message and a rebuke to the political order in national elections Monday that threatened to plunge the country into political paralysis after early results failed to produce a clear winner.

Analysts said the best-case scenario would be a shaky coalition government, which would once again expose Italy and the eurozone to turmoil if markets question its commitment to measures that have kept the budget deficit within a tolerable 3 percent of gross domestic product. News of the stalemate sent tremors through the financial world, sending the Dow Jones industrial average down more than 200 points.