BASEL, Switzerland: A year after its rivals Ciba Geigy and Sandoz combined to create the world's largest drug company just across town, Roche Holding is looking to catch up. Monday, the Swiss giant announced it will buy holding company Corange Inc. for $11 billion in a deal that will boost Roche's drug operations from tenth place to sixth in the worldwide medical diagnostics market. Roche will assume Corange's holdings in Germany's Boehringer Mannheim, a market leader in cardiovascular and cancer treatments. It will also gain an 84.2 percent stake in DePuy, a Warsaw, Indiana-based manufacturer of orthopedic products. The final price of the deal is subject to negotiation. If approved by regulatory authorities, however, the takeover is expected to bring a round of layoffs. Though Roche declined to give specific figures, the Swiss industrial labor union GBI said it feared job cuts of 15 percent from the 70,000 workers now employed at the combined companies. Roche finance chief Henri B. Meier predicted the takeover would soon increase earnings, but that in the current year it will "dilute" profits. American investors will have their say when U.S. markets open Tuesday.