Wendy's International, Dublin, Ohio, will acquire Canadian restaurant chain Tim Hortons for about $400 million. It's the 26-year-old hamburger chain's first acquisition. Wendy's already operates 13 co-branded units in Canada with Tim Hortons, a 1,000-unit quick service breakfast chain selling donuts, baked goods and coffee. Wendy's plans to build another 20 co-branded restaurants in Canada this year and will use the Tim Hortons concept to build its breakfast business in the U.S., where two co-branded test units are already under construction, in Minneapolis and Detroit. Bates Worldwide, New York, handles Wendy's $140 million account. Enterprise Advertising, Toronto, handles Tim Hortons.