Asparagus Risotto

1 pound asparagus, trimmed, cut into 2-inch lengths
5 cups canned low-salt chicken broth
2 tablespoons olive oil
1/2 cup chopped onion
1 1/2 cups arborio rice or medium-grain white rice
1/2 cup dry white wine
6 tablespoons (3/4 stick) butter
3/4 cup freshly grated Parmesan cheese (about 3 ounces)

Blanch asparagus pieces in large pot of boiling, salted water 2 minutes. Drain. Rinse asparagus under cold water. Drain asparagus well.
Bring chicken broth to simmer in small saucepan. Reduce heat to low and keep broth hot. Heat olive oil in heavy large saucepan over medium heat. Add chopped onion and sauté until translucent, about 4 minutes. Add rice and stir 3 minutes. Add dry white wine and cook until liquid evaporates. Continue cooking until rice is tender but still slightly firm in center and mixture is creamy, adding chicken broth 1 cup at a time and stirring almost constantly, about 20 minutes. Add blanched asparagus pieces and stir until heated through, about 2 minutes. Remove from heat. Add 6 tablespoons butter and stir until incorporated. Stir in grated Parmesan cheese. Season risotto to taste with salt and pepper.