RIYADH: A landmark accord on monetary union among four members of the six-nation Gulf Cooperation Council (GCC) was signed here yesterday. This long-awaited common currency agreement signed by Saudi Arabia, Kuwait, Bahrain and Qatar at the Conference Palace here calls for the establishment of the GCC Monetary Council this year that will pave the way for setting up a regional central bank in Riyadh. “This is a landmark accord,” said Saudi economist Ihsan Bu-hulaiga. “But it is highly desirable that other two members should also come on board and I am hopeful that the UAE and Oman will join at some point of time.”