Dollar Tree
A view of the sign outside the Dollar Tree store in Westminster, Colorado on Feb. 26, 2014. Reuters/Rick Wilking

(Reuters) - U.S. discount store chain Dollar Tree Inc offered to buy rival Family Dollar Stores Inc for an enterprise value of about $9.2 billion.

Dollar Tree's offer of $74.50 per share in cash and stock represents a premium of about 23 percent over Family Dollar's close of $60.66 on Friday.