RABAT (AFP) - Morocco on Thursday said it had lost confidence in the United Nations' envoy for Western Sahara, Christopher Ross, claiming he made "biased and unbalanced" decisions concerning the disputed region.

"The contrasting behaviours of Mr. Ross differ from the guidelines agreed by negotiations at the Security Council. Because of this, Morocco has decided to withdraw its confidence" in Ross, the government said in a statement.

Ross in March led informal talks in New York between Morocco and the Polisario Front -- a group working to win the independence of Western Sahara from Morocco. The talks made little head way, Ross has said.

The statement provided no additional details except to say Morocco was concerned about US diplomat Ross's behaviour.

Western Sahara is a former Spanish colony that was annexed by Morocco in 1975.

Rabat has proposed making the area largely autonomous but keeping it under Moroccan sovereignty. The Polisario Front, which is supported by Algeria, has rejected the proposal.