BELGRADE, May 21 (Xinhua) -- The referendum on Montenegro's possible independence ended at 9 p.m. (1900 GMT) on Sunday after a13-hour voting with a record turnout. Unofficial and official preliminary results are expected respectively on Sunday night and on Monday morning.

    Under conditions mediated by the European Union, Montenegro's independence from the state union of Serbia-Montenegro will not be valid unless the referendum passes the threshold of 55 percent of valid votes with a turnout of at least half of the mountainous republic's 484,718 registered voters. Enditem