* Protests erupt in capital as rebels sweep south
* Government minister appeals to Paris for help (Recasts with minister, adds U.N. evacuation)
BANGUI, Dec 26 (Reuters) - A government minister in the Central African Republic called on Wednesday for French soldiers stationed in the country to intervene to stop rebels who have swept south in recent weeks and are now threatening the capital.
The appeal came as hundreds of people protested outside the French Embassy in Bangui, the capital, throwing stones at the building and tearing down the French flag in anger at a rebel advance through the north of the country.
The rebel push through a string of towns in recent weeks has highlighted the fragility of the land-locked nation which has known little else apart from instability since independence from France in 1960.
A United Nations official said all non-essential staff would be evacuated due to the worsening security situation.
French broadcaster RFI on Wednesday quoted Josue Binoua, the CAR's minister for territorial administration, calling for French intervention.
"We are waiting for France to come to our help!" he was quoted as saying on RFI's website in response to a question over what Bangui expected from France's 200 troops stationed in the capital.
French military officers act as advisors to the CAR's army and Paris in the past has helped prop up or oust governments. However, France is increasingly reluctant to directly intervene in conflicts in its former colonies.
Vincent Floreani, deputy spokesman in the French foreign ministry, did not comment on the specific appeal but said the crisis had to be resolved through dialogue.
A Reuters reporter at the scene of Wednesday's protests said some protesters had accused France of backing the rebels while others had demanded French forces in the country help the army fight off the rebel push.
A smaller group of protesters, mainly youths linked to the ruling party, gathered outside the U.S. Embassy and stoned cars carrying white passengers, the reporter said.
"Protesters who were passing in front of the (French) embassy threw stones at the embassy and some of them were able to get into the compound but they were repulsed," Floreani told Reuters.
On Tuesday, the rebels, known as the Seleka alliance, took the central town of Kaga Bandoro despite the presence of troops from neighbouring nations who were meant to shore up the weak national army.
An estimated 150 Chadian soldiers dispatched to block the rebel push are positioned in Sibut, the last remaining town between rebel positions and Bangui.
President Francois Bozize came to power in 2003 after a brief war and has repeatedly relied on foreign intervention to fend off rebellions and the spill-over from conflict in neighbouring Chad and Sudan.
Air France's weekly Paris-Bangui flight had to turn back "due to the situation in Bangui", a spokeswoman said.
The airline said its next flight for Bangui on Jan. 2 would go ahead. (Reporting by Paul-Marin Ngoupana and Leigh Thomas in Paris; Additional reporting and writing by David Lewis; Editing by Andrew Osborn)