The anti-immigrant party led by rightwing Interior Minister Matteo Salvini earned 27 to 31 percent of the votes, according to projections by three different pollsters unveiled by state TV broadcaster RAI.
Pro-European, center-left Democratic Party — Italy’s major opposition force — followed with 21 to 25 percent, while populist and Eurosceptic Five Star Movement would come third with 18.5 to 22.5 percent.
If these exit polls were confirmed by the vote count, this will make a lower-than expected result for the M5S, which is the current partner of the League in the coalition government, and was projected to score at least as the second-best during the campaign.
Another major contender, center-right Forza Italia party, earned 8 to 12 percent of the votes.
As the fourth most populous country in the European Union (EU), Italy had to elect 76 Members of the European Parliament (MEPs), which counts 751 seats overall.
Yet, three of the Italian newly-elected lawmakers will have to wait, and take their seats only after Britain leaves the Union, and its lawmakers play no further role in the EU assembly, thus allowing their seats to be redistributed among the remaining 27 member states of the bloc.
Polling stations here opened at 7 a.m. and closed at 11 p.m. local time.
Some 50.9 million people were eligible to vote out of a 60.3-million population, and turnout was estimated at 52.95 percent at the closure of the polling stations, according to the Interior Ministry.
In the same electoral day, some 16 million Italians were also called to renew municipal councils, and 3.6 million to vote for regional governments.
Official results for the European parliament were expected early on Monday.
The vote to elect the new EU assembly was held in each of the 28 EU current member states between May 23 and May 26, with 427 million eligible voters across the continent.
