GRAINS-Wheat hovers near three-week high on demand optimism

U.S. wheat futures edged higher on Tuesday, hovering near a three-week high hit in the previous session, as expectations of an imminent uptick in demand for North American supplies underpinned gains. FUNDAMENTALS * The most active wheat futures on the Chicago Board Of Trade were up 0.1 percent at $5.20-1/2 a bushel, as of 0126 GMT. In the previous session, wheat futures closed 3.3 percent firmer, when prices hit $5.20-3/4 a bushel, the highest