Voters chose individual candidates as well as from party lists
Romania's opposition Liberal Democrats and Social Democrats are running neck-and-neck in general elections, partial results show.
With 93% of the vote counted, President Traian Basescu's centrist Liberal Democrats (PDL) had won about 33%.
The ex-communist Social Democrats (PSD) had also taken 33%, while the ruling National Liberals (PNL) polled 18%.
Tough coalition talks are expected if these figures are confirmed, as none of the parties would have a majority.
Earlier, exit polls predicted that the Social Democrats would win the elections - the first polls since Romania joined the EU at the beginning of last year.
'Strains of governing'
Squabbles between President Traian Basescu of the PDL and Prime Minister Calin Popescu Tariceanu of the PNL wrecked their coalition in 2007.
Since then Mr Popescu Tariceanu's minority government has been tacitly supported in parliament by the PSD and an ethnic Hungarian party, which is polling about 6% of the vote in Sunday's elections.
President Basescu said before the polls that he would prefer a centre-right government.
He is not obliged by law to nominate a prime minister from the winning party. He proposes a candidate, and parliament then votes on whether to validate his choice.
Some 18m voters cast votes for both chambers of the 452-strong parliament on Sunday.
Officials said turnout was just under 40%.
In the 19 years since the Romanian revolution, the left has traditionally shown more discipline while centre-right alliances have achieved dramatic election victories but have broken up under the strains of governing, BBC Eastern Europe correspondent Nick Thorpe says.