By Angus McDowall
RIYADH (Reuters) - Saudi Arabia, the United Arab Emirates (UAE) and Bahrain said on Wednesday they were withdrawing their ambassadors from Qatar because Doha had not implemented an agreement among Gulf Arab countries not to interfere in each others' internal affairs.
The move, conveyed in a joint statement by the three countries, is unprecedented in the three-decade history of the Gulf Cooperation Council, a pro-Western alliance of Saudi Arabia, Bahrain, Kuwait, Qatar, UAE and Oman.
Qatar has been a maverick in the conservative region Of hereditary monarchies, backing Islamist groups in Egypt, Syria and elsewhere in the Middle East that are viewed with suspicion or outright hostility by some fellow GCC members.
Saudi Arabia and the UAE are fuming especially over Qatar's support for the Muslim Brotherhood, an Islamist movement whose political ideology challenges the principle of dynastic rule, and by its playing host to its spiritual leader Yusuf Qaradawi.
The statement said GCC members had signed an agreement on November 23 not to back "anyone threatening the security and stability of the GCC whether as groups or individuals - via direct security work or through political influence, and not to support hostile media".
Saudi and other Gulf Arab officials often complain in private about Qatar's al Jazeera television station, which they see as being openly supportive of the Brotherhood and critical of their governments. Al Jazeera says it is an independent news service giving a voice to everyone in the region.
The Saudi-UAE-Bahraini statement said GCC foreign ministers had met in Riyadh on Tuesday to try to persuade Qatar to implement the agreement.
"But unfortunately, these efforts did not result in Qatar's agreement to abide by these measures, which prompted the three countries to start what they saw as necessary, to protect their security and stability, by withdrawing their ambassadors from Qatar starting from today, March 5 2014," the statement said.
Qatar's foreign ministry said it would respond later.
Qatar has played a weighty role in promoting Arab Spring protests against authoritarian rule, saying it has stood consistently with ordinary Arabs against oppression. It has sought to elevate its international profile through a global investment push, the 1990s launch of al Jazeera and its successful bid to host the 2022 soccer World Cup tournament.
A source close to the Saudi government said pressure on Qatar would continue until it made tangible steps to change its policies. "They have to divert their position on many issues and we are waiting for real signs of this, not just talk."
A Gulf diplomatic source said: "We expect Qatar to react to what just happened and withdraw from the policies and ideas that have isolated it as a country. As people we are very brotherly to one another and we don't want things to escalate."
(Reporting by Angus McDowall in Riyadh, Reem Shamseddine in al-Khobar, Rania el Gamal in Dubai and Amena Bakr in Doha; Writing by William Maclean; Editing by Mark Heinrich)