WARSAW (Reuters) - Poland's largest opposition party Law and Justice (PiS) has taken the lead in regional elections held on Sunday, an exit poll showed, their first victory over the ruling Civic Platform (PO) party in a nationwide vote in nine years.
PiS won 31.5 percent of the vote in elections to provincial assemblies on a nationwide basis, versus 27.3 percent support for PO, an exit poll by pollster Ipsos conducted for Polish televisions TVP, TVN24 and Polsat showed.
The regional elections are held every four years to chose mayors, provincial assembly members and other local authorities.
The junior ruling coalition partner PSL has won 17 percent of votes, while the leftist SLD party secured 8.8 percent, the exit poll showed.
In the last regional elections in 2010, PO won 30.9 percent of the votes, followed by PiS on 23.1 percent and the PSL party with 16.3 percent.
The state election commission PKW said on Monday that the release of official election results will be delayed because of technical problems with the IT system used by the commission.
Poland is due to hold general and presidential elections next year.
(Reporting by Marcin Goettig; Editing by Susan Fenton)