Minnetonka, Minn.-based UnitedHealth will pay $43.50 a share for its Las Vegas-based rival, giving holders a 21% premium to Friday's closing prices. UnitedHealth said the deal adds to its portfolio in the fast-growing southwestern U.S.
UnitedHealth expects the deal to add 4 cents a share to its earnings over the first 12 months. The company said it continues to expect to buy back $4 billion to $4.5 billion in stock in 2007.
Sierra rose $5.10 to $41.