DEERFIELD, Ill. (AP) — Walgreen is expanding its supply agreement with AmerisourceBergen through a 10-year deal that gives the nation's largest drugstore chain an ownership stake in the pharmaceutical wholesaler.

Walgreen Co. says AmerisourceBergen Corp. will replace primarily Cardinal Health Inc. in supplying it with pharmaceuticals. Previously, AmerisourceBergen had supplied only some specialty drugs for Walgreen, which operates more than 8,000 drugstores.

Walgreen and European health and beauty retailer Alliance Boots receive the right to buy up to 7 percent of AmerisourceBergen's shares and warrants to purchase an additional 16 percent. Walgreen owns a stake in Alliance Boots.

AmerisourceBergen says it expects that the deal will add $28 billion in revenue and about 20 cents per share in earnings to its fiscal 2014 performance, not counting costs tied to the agreement.

AmerisourceBergen shares rose $2.69, or 5.6 percent, to $50.99 in premarket trading Tuesday.