Israel's election commission has revised the results of last week's vote, giving the Labour party one fewer seat, and an Arab party an extra seat.
The revised result may make it more difficult for Olmert to form a coalition
The revision, following a recount of ballots in some Arab towns, gives Labour 19 seats.
This is 10 fewer than the Kadima party of acting PM Ehud Olmert, which is expected to head the next government.
The United Arab List will now have four seats, giving Arab parties a total of 10 in the 120-seat parliament.
FINAL RESULTS (revised 3 April)
1. Kadima: 29 seats, centrist
2. Labour: 19 seats, centre-left
3. Shas: 12 seats, ultra-Orthodox
4. Pensioners: 7 seats, single-issue
5. Torah Judaism: 6 seats, ultra-Orthodox
6. Meretz: 5 seats, left-wing
7. Israel Beitenu: 11 seats, Russian emigres, far-right
8. Likud: 12 seats, right-wing
9. Arab parties: 10 seats
10. National Union/Religious: 9 seats, far-right, settlers
The revised result means that if Mr Olmert were to become prime minister he would not be able to rely on centre-left Jewish parties alone for a majority in the parliament.
Mr Olmert is still not expected to have great difficulty in forming a coalition government.
Arab Israeli parties had demanded a recount of ballots in some Arab dominated towns.
The results from five polling stations were logged incorrectly, a press release by the Central Election Commission said.
On Sunday, Israel's president began meetings with the main political parties on who should form a government following the general election.
After hearing recommendations, Moshe Katsav will name a leader to put together the next ruling coalition.
This process could take up to six weeks.