NEW YORK (AP) — Citi Investment Research analysts said Tuesday that CVS Caremark Corp. and some smaller pharmacy benefits management companies should benefit in 2012 and 2013 from the split between Walgreen Co. and leading PBM Express Scripts Inc.

Analyst Deborah Weinswig downgraded Walgreen shares to "Sell" from "Neutral," citing the business Walgreen is losing after it stopped filling prescriptions for Express Scripts on Jan. 1. Weinswig placed shares of CVS Caremark, which owns a large drugstore chain and a pharmacy benefits management business, on her list of stocks with a top recommendation.

Walgreen said in June that it would stop filling prescriptions for Express Scripts at the end of 2011, when a contract between the two companies ran out. The companies were unable to agree on how much money Express Scripts should pay Walgreen to fill prescriptions. The dispute has taken a chunk out of Walgreen's sales, but the Deerfield, Ill., company said it would prefer to lose that business rather than fill unprofitable prescriptions.