By Manoah Esipisu

South Africa said on Thursday it had opened full diplomatic ties with Western Sahara this week because Morocco was not ready to discuss the region's self-determination.

The decision by South Africa, one of Africa's diplomatic heavyweights, was a setback for Morocco's efforts to convince the international community it has sovereign rights over Western Sahara, where it has long fought the separatist Polisario Front.

Morocco said after Wednesday's announcement that it was recalling its ambassador in Pretoria to protest against a "partial, surprising and inopportune" decision.

"It is a big step because we are committed to Western Sahara's self-determination," South African Foreign Minister Nkosazana Dlamini-Zuma said in an interview.

South Africa had delayed establishing full ties with Western Sahara and the Polisario since the end of apartheid in 1994, Dlamini-Zuma said, but UN envoy James Baker's resignation in June showed a UN process dealing with the region was going nowhere.

"Once that process was stopped and Baker resigned and Morocco said its (sovereignty claim) was not negotiable, then we were left with no choice," she told Reuters at the opening of the Pan-African Parliament's new home in South Africa.

Morocco is not a member of the 53-member African Union, because the group recognises Western Sahara.

Dlamini-Zuma said Pretoria had not been officially informed of Rabat's decision to withdraw its ambassador and would not comment until Morocco had made a formal announcement.

President Thabo Mbeki, in a speech to the Pan African Parliament, called on the international community to press for Western Sahara's self-determination in the same way as it had done to bring about the end of South Africa's apartheid system of racial segregation.

"It is a matter of great shame and regret to all of us that, nevertheless, the issue of self-determination for the people of Western Sahara remains unresolved," Mbeki said.

"This presents all of us with the challenge to ensure that we do everything possible to ensure that these sister people also enjoy this fundamental and inalienable right, whose defence by the entirety of our continent brought us our freedom."

Salah Abdi Mohammad, one of Western Sahara's five representatives in the new 265-member Pan-African Parliament, said the move "confirms South Africa's position as a champion of democracy and human rights on the continent".

Morocco seized sparsely populated Western Sahara in 1975 after colonial power Spain pulled out, triggering a bitter guerrilla war with the Polisario Front.

The United Nations brokered a ceasefire in 1991 but its efforts stalled when Baker, a former U.S. secretary of state, resigned after seven years of trying to make progress in resolving the dispute.

African heavyweights including Algeria, the Polisario Front's main backer, and Nigeria, have diplomatic ties with the Sahrawi Arab Democratic Republic the Polisario set up in 1976.

Morocco rejected a proposal by Baker to make the area - rich in phosphates and fisheries and believed to have potential offshore oil - a semi-autonomous part of Morocco for four to five years, followed by a referendum on independence.

(Additional reporting by MacDonald Dzirutwe)