Marion Laboratories and Dow Chemical said they...

Marion Laboratories and Dow Chemical said they signed a definitive agreement to combine their pharmaceutical companies and expect the deal to be completed by the fall. On Monday, Marion and Dow’s Merrell Dow Pharmaceuticals, based in Cincinnati, announced a preliminary merger agreement . . . Hospital Corp. of America has announced an agreement in principle to sell its majority-owned Australian unit to Mayne Nickless Ltd., Melbourne, Australia.