Cook carrots in water to cover in large saucepan until almost tender, 8 to 10 minutes; do not overcook (you do not want mushy carrots). Drain, reserving the cooking liquid for soup if desired.
Combine cider vinegar, vegetable oil, sugar, mustard, Worcestershire sauce and tomato soup in large bowl. Add carrots; toss to coat. Add green pepper and chopped onion. Cover and refrigerate.
