SEOUL (AFP) - South Korea's main opposition party elected a new leader on Saturday who pledged to end factional infighting and move to the right towards more centrist policies.

Four-term lawmaker Kim Han Gil, 60, was elected as the new leader of the Democratic Party (DP), previously known as the Democratic United Party, at a leadership election in which he defeated rival Lee Yong Sup.

"I will bring an end to factional politics... We will build a new DP, a bigger DP and a winning DP," Mr Kim said in an acceptance speech.

Earlier on Saturday, the centre-left party officially changed its name to the DP and amended its constitution, adopting more centrist policies.

The liberal opposition party has suffered a series of election defeats, including the presidential vote in December last year.

Mr Kim is from a minor group of lawmakers within the DP, which has been dominated by loyalists of former late president Roh Moo-Hyun.

The DP has been in disarray since its presidential candidate Moon Jae-In lost to the ruling conservative New Frontier Party's Park Geun-Hye in the December election.

It failed to win a single seat in last month's parliamentary and local council by-elections.