In a large bowl, combine 2 cups all-purpose flour, whole wheat flour, rye flour, sugars, yeast and salt. In a small saucepan, heat the milk, water and oil to 120°-130°. Add to dry ingredients; beat until smooth. Stir in enough remaining all purpose flour to form a soft dough.
Turn onto a floured surface; knead until smooth and elastic, about 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and let rise in a warm place until doubled, about 1 hour.
Punch dough down. Turn onto a lightly floured surface; divide into four pieces. Roll each into a 15-in. rope. Twist two ropes together; pinch ends to seal. Repeat with remaining dough. Place in two greased 9x5-in. loaf pans. Cover and let rise until doubled, about 45 minutes.
Bake at 375° for 30-35 minutes or until golden brown. Remove from pans to wire racks to cool.