ROME  In a mood of national pessimism, Italians began voting Sunday in a race between the conservative billionaire Silvio Berlusconi, seeking a third term as prime minister, and Walter Veltroni, a former mayor of Rome.

The campaign, in a nation that has had more than 60 governments since World War II, has been considered lackluster, with voters skeptical of change no matter who wins at a time of economic trouble and political stagnation.

Some pollsters predicted an especially low turnout, in a nation where turnout is usually high. The Interior Ministry reported that on the first day of two days of voting, 48.9 percent of eligible Italians cast ballots for the lower house of Parliament, the Chamber of Deputies. In national elections two years ago, which Mr. Berlusconi lost, the first-day turnout was 52.2 percent.

With economic growth again near zero and crises involving trash and the national airline unresolved, many Italians have said that they want change, but that neither candidate seemed capable of providing it.