Olmert has said that in the absence of progress in peace talks with Palestinians, he supports dismantling some Jewish settlements in the West Bank and imposing a final border on the Palestinians.
The exit polls forecast the center-left Labor Party taking up to 22 parliament seats, while the right-wing Yisrael Beitenu party, popular with Russian immigrants to Israel, is projected finishing as high as third, with 12 or more seats.
The projections showed the formerly governing right-wing Likud party getting only about 12 seats.
Officials said the turnout in the elections was about 63 percent, the lowest in Israeli history.
(compiled from agency reports)