NEW YORK (AP) — Shares of Bristol-Myers Squibb Co. slid in Friday trading, and an analyst lowered his rating on the stock because he no longer believes the drugmaker is likely to be bought out. Tim Anderson of Bernstein Research downgraded Bristol-Myers shares to "Market Perform" from "Outperform" due to the reduced chance of a sale, and because he believes the stock is expensive relative to the company's earnings. In afternoon trading, shares of the New York-based company fell $1.07, or 5 percent, to $20.26. Concerns about Food and Drug Administration rulings for diabetes drug candidates, including Onglyza, from Bristol-Myers and its partner AstraZeneca PLC, may have pressured the stock. In June 2008, Anderson said there was a good chance Bristol-Myers was going to be sold. But since then, the potential buyers have either made a major acquisition — including Pfizer Inc.'s purchase of Wyeth and Merck & Co.'s buyout of Schering-Plough Corp. — or said they are not planning one, Anderson wrote. He said management for GlaxoSmithKline PLC, Eli Lilly & Co., AstraZeneca and Sanofi-Aventis have ruled out buying a large drugmaker like Bristol-Myers, and it's not likely Johnson & Johnson or Abbott Laboratories would buy the company either. Anderson lowered his price target to $22 per share from $26. Over the last year, shares of Bristol-Myers have traded between $16 and $23.98, which in Anderson's view makes Bristol-Myers one of the priciest stocks in its sector. The analyst said Bristol-Myers may make a smaller acquisition of its own, using some of its $9 billion in cash. The company faces a wave of important patent expirations in the coming years, as drugs like its blood-thinner Plavix will be vulnerable to generic competition. Officials at Bristol-Myers weren't immediately available to comment. Anderson wrote that Bristol-Myers will probably extend a marketing agreement on the schizophrenia drug Abilify with Japanese drugmaker Otsuka to help gain more revenue, but it needs to do more.