GENEVA, May 5 (Reuters) - A group of countries led by four Western states is set to request an urgent meeting of the U.N. Human Rights Council on the Sudan crisis next week, a document showed on Friday.

The letter dated May 5 showed that Britain, the United States, Germany and Norway are set to ask the council's president to convene a meeting to examine the surge in violence in the country since April 15.

Diplomats told Reuters they had the backing of at least a third of the 47-member council, as required by its rules.

(Reporting by Emma Farge Editing by Miranda Murray)