Banana-Nut Bread

1 C ripe bananas, mashed
1/3 C lowfat buttermilk
1/2 C brown sugar, packed
1/4 C margarine
1 egg
2 C all-purpose flour, sifted
1 tsp baking powder
1/2 tsp baking soda
1/2 tsp salt
1/2 C pecans, chopped