Rival parties were neck-and-neck Wednesday in South Korea's closely contested legislative election, a key test of sentiment before December's presidential vote, according to exit polls conducted by three major TV stations.

The polls showed a tight race between President Lee Myung-bak's conservative Saenuri Party and the main opposition centre-left Democratic United Party.

An exit poll by public broadcaster KBS predicted that the ruling Saenuri Party and the main opposition will both win between 131-147 seats out of the total 300 seats up for grabs.

Another poll by MBC showed the ruling party winning between 130-153 seats against the DUP's 128-148 seats. An SBS TV poll forecast the ruling party winning between 126-151 seats and the opposition party between 128-150 seats.