GRAINS-Wheat slips after two-day runup amid plentiful supply

MANILA, Nov 20 (Reuters) - Chicago wheat futures edged lower on Monday after a two-day advance, pressured by abundant global supplies, while corn and soybeans steadied after sharp gains in the previous session. FUNDAMENTALS * Wheat for December delivery on the Chicago Board of Trade was down 0.6 percent at $4.24-3/4 a bushel by 0127 GMT. * Global wheat demand has been lean at a time of bountiful supply with Russia looking at a record harvest. * Exports of Euro