(Adds delivery of Abyei case to arbitration court)

By Skye Wheeler

JUBA, Sudan, July 12 (Reuters) - South Sudan's army said on Saturday it had finished pulling out of the oil-rich Abyei area where southern troops clashed with Khartoum's forces in May, but accused the northern army of foot-dragging on its own pullout.

"We have pulled out. The forces are south of Abyei," Sudan People's Liberation Army (SPLA) Spokesman Peter Parnyang said, adding that the former southern rebel movement was "seriously disappointed" that the northern army remained in the area.

"They are dragging their feet," he said. Battles between the two forces in Abyei led to the displacement of some 50,000 people and killed scores, causing widespread concern a 2005 north-south peace deal that ended decades of war could unravel.

Both sides missed a June 30 withdrawal date agreed by the SPLA's political arm -- the Sudan People's Liberation Movement -- and Khartoum's ruling National Congress Party.

A senior official in the U.N. peacekeeping mission in Sudan said the SPLA's redeployment had been verified by their monitors. He did not give numbers of northern forces still in the area but said they were moving.

An SPLA solider shot and wounded a U.N. and a northern army monitor last week and the northern withdrawal stopped, he said. "But they have now restarted," he added.

Under a June roadmap agreement signed by the two sides, the area is to be governed by a temporary administration led by an SPLM official with a northern deputy. North-south disagreement over the area has meant it has lacked formal administration since the peace deal.

The roadmap also agreed to refer the issue of Abyei's disputed borders -- which would decide whether one of Sudan's two largest oil fields is in north or south Sudan -- to the Permanent Court of Arbitration in The Hague.

On Friday, a joint north-south delegation officially delivered the case to the court, Sudan's state news agency SUNA said.

Abyei and the south will vote in separate referendums in 2011 on secession from the north.

Some 2 million people died in Sudan's north-south war that also displaced around 4 million. It is separate from the Darfur conflict in the west of the country. (Additional reporting by Opheera McDoom in Khartoum) (Writing by Skye Wheeler; Editing by Caroline Drees) (For more news and information on humanitarian issues visit www.alertnet.org)

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