Sweden's Social-led bloc is struggling to form a government after it ousted the center-right ruling coalition in Sunday's parliamentary election but fell short of a majority.

After eight years in power, conservative Prime Minister Fredrik Reinfeldt conceded defeat after his bloc lost support with 142 seats in the 349-seat Parliament while the opposition Social Democrat-led Red-Green won 158 seats.

The election also saw a surge in support for anti-immigration Sweden Democrats party which more than doubled its seats to 49 seats, from the previous election in 2010. However, it is unlikely to attain its goal of sharply reducing immigration because all other parties favor a liberal asylum policy.

Government formation talks are expected to last days as the Social Democrats try to form a new majority coalition.