Walgreen Co., the biggest U.S. drugstore chain, said Friday it will acquire the home infusion business of Omnicare Inc. in exchange for its long-term care pharmacy business.

Financial terms of the deal, which is expected to close before Nov. 15, were not disclosed.

Walgreen, based in Deerfield, Ill., said it decided to leave the long-term care pharmacy business because, on a stand-alone basis, it lacked the necessary scale "to effectively grow to a leading position in its sector without significant additional investment."

"By divesting our long-term care pharmacy business, we are able to have a stronger focus on our overall growth strategy while taking advantage of a specific opportunity to grow our infusion services," Walgreen CEO Greg Wasson said in a statement from both companies.

Omnicare has six home infusion locations in Maryland, Nevada and Virginia, among other states. It will buy the assets at Walgreen's long-term care pharmacy locations in Colorado, Texas, Florida, Georgia and Maryland.

Omnicare, headquartered in Covington, Ky., dispenses drugs to nursing homes and long-term care facilities. It said the deal helps the company expand its presence in the growing senior market.

Shares of Walgreen rose 40 cents to $28.70 at the start of trading Friday. Omnicare stock climbed 39 cents to $20.94.