(Adds letter to French president)
VIENNA, April 10 (Reuters) - U.N. Secretary-General Ban Ki-moon on Thursday renewed his appeals for sustained human rights monitoring in the disputed territory of northern Africa's Western Sahara and warned against unfair exploitation of the region's natural resources.
The comments were included in Ban's latest report on Western Sahara to the 15-nation U.N. Security Council, an advance copy of which was obtained by Reuters.
Morocco took control of most of the territory in 1975 when colonial power Spain withdrew, prompting a guerrilla war for independence that lasted until 1991 when the United Nations brokered a cease-fire and sent in a peacekeeping mission known as MINURSO.
Ban said he welcomed Morocco's willingness to allow special investigators from the U.N. Human Rights Council to visit the territory and the Polisario Front independence movement's willingness to work with United Nations rights bodies.
"The end goal nevertheless remains a sustained, independent and impartial human rights monitoring," Ban said.
While Ban did not say it directly, U.N. officials and diplomats say that he would like the U.N. mission in Western Sahara to take on monitoring human rights violations in the territory, but Morocco, backed by France, has vigorously resisted the idea.
The renewal of the mandate of the peacekeeping mission marks an annual battle in the Security Council between France, which defends Morocco's position, and a number of African and Western nations supporting Polisario.
After sending the report to the council on Thursday, the United Nations issued at least two revised versions of it over the course of several hours. The latest version removes the term "monitoring mechanism" and only refers to "monitoring."
Ahmed Boukhari, the Polisario's U.N. representative, said he was disappointed Ban's report did not go further, adding that Rabat and Paris were putting pressure on the world body.
"Morocco with the help of France are placing the U.N. in a very uncomfortable situation," he said in an email.
French U.N. Ambassador Gerard Araud rejected the allegation, saying in a statement to Reuters, "France formally denies any interference with the U.N. Secretariat."
Diplomats at the Moroccan mission did not immediately respond to a request for comment.
OIL AND GAS POTENTIAL
Former U.N. special envoy to Western Sahara Peter van Walsum and the former deputy chief of MINURSO Frank Ruddy wrote an open letter to French President Francois Hollande on Thursday urging to him to "make a strong call for human rights monitoring to be included in the mandate" of the U.N. mission in Western Sahara.
Western Sahara, which is slightly bigger than Britain, has under half a million people known as Sahrawis.
Some African countries, Britain, the United States and other Western nations have repeatedly called for U.N. peacekeepers to be given the task of monitoring alleged human rights abuses.
Ban recommends renewing the mandate of MINURSO for 12 more months and 15 more U.N. observers to join the 225 already there.
The report touches on the sensitive issue of exploitation of Western Sahara's resources. It is rich in phosphates - used in fertilizer - and, potentially, offshore oil and gas.
"In light of increased interest in the natural resources of Western Sahara, it is timely to call upon all relevant actors to 'recognize the principle that the interests of the inhabitants of these territories are paramount'," Ban said, citing the United Nations Charter.
French energy giant Total and U.S. oil explorer Kosmos have joined in the hunt for oil off the coast of Western Sahara.
Morocco, Total and Kosmos have all pledged to abide by international standards and pledged that the local population would benefit from discoveries.
Total did not have an immediate response to Ban's report when contacted by Reuters.
Kosmos said in a statement: "Our activities are currently focused solely on exploration. ... If we were to make a commercially viable discovery, then we would only proceed with development in accordance with international law and best practices," it said.
Rabat wants Western Sahara to be an autonomous part of Morocco. Polisario instead proposes a referendum among ethnic Sahrawis that includes an option of independence, but there is no agreement between Morocco and Polisario on who should participate in any referendum.
Attempts to reach a lasting deal through U.N.-mediated talks have floundered. In the report, Ban renewed his call for a revival of the Western Sahara talks aimed at securing a political deal and some form of self-determination for the region. (Reporting by Louis Charbonneau; Editing by Cynthia Osterman and Richard Chang)