Tasty Baking sued to foil a snack firm merger.

Tasty Baking Co. and its subsidiary, Tastykake, asked a federal judge in Philadelphia to grant a preliminary injunction halting the merger of Drake Bakeries into the Continental Baking Co. unit of Ralston Purina. Tasty Baking said the merger would substantially lessen competition in the snack cake and pie industry. A Ralston Purina spokeswoman declined to comment because company officials had not seen the suit.