Heat oil in a large saucepan over medium heat; add onion and cook 5 minutes, stirring occasionally. Stir in wine and cook 1 minute; sprinkle in flour and cook 1 minute.
Gradually stir in milk and chicken broth. Drain liquid from clams into measuring cup. Add 1 cup of the clam juice to the pot and reserve the clams. Add potatoes, cover and simmer 10 minutes.
Add reserved clams, corn, Old Bay, salt and pepper. Bring to a simmer to heat through. Turn off heat and stir in parsley.
Serve with tossed salad and crusty bread, if desired.