GENEVA (Reuters) - The United Nations has invited Morocco, Algeria, Mauritania and the Polisario Front, a Western Sahara independence movement, for talks in Geneva on the conflict in the desert region next December, a U.N. spokeswoman said on Monday.

U.N. efforts have repeatedly failed to broker a settlement over the territory, contested between Morocco and the Algerian-backed Polisario since Spanish colonial power left in 1974.

U.N. Special Envoy for Western Sahara, Horst Kohler, has invited the foreign ministers of Morocco, Algeria and Mauritania as well as the secretary general of the Polisario Front for a meeting in Geneva, the spokeswoman said.

Morocco has insisted that Algeria should be brought to the negotiation table accusing it of backing Polisario militarily and financially. Algeria denies the accusations.

“The purpose of the meeting is to take stock of developments since the last round of negotiations, address regional issues, and discuss the next steps in the political process on Western Sahara,” the U.N. spokeswoman said.

The talks come after Kohler’s second visit to the region in June and after his briefing to the Security Council on 8 August, during which he announced his intention of organizing a meeting before the end of the year.

In 1991 the U.N. brokered a ceasefire between Morocco and the Polisario and supported a referendum on the region’s future, including the possibility of independence. The vote never happened.

Morocco has offered autonomy to Western Sahara, a thinly populated region that has rich fishing waters and phosphate deposits, and may also have oil and gas reserves.

Polisario and its ally Algeria reject this and say they want a referendum, with independence for Western Sahara as one of the options.