Wickes Cos. of Santa Monica and the Larkin Group Inc. of Atlanta jointly announced that Wickes and the shareholders of the Larkin Group have reached an agreement in principle whereby Wickes will acquire the Larkin Group . . . United Airlines will pay a $45,000 fine to settle charges that its Apollo computerized reservation system displayed international air fares in a biased manner, the Transportation Department said . . . Perkins Coie, the Northwest's largest law firm, and Johnsen, Manfredi & Thorpe of Los Angeles announced their merger effective March 1. The combined firm will operate as Perkins Coie.