NEW YORK (Reuters) -- Bristol-Myers Squibb Co. on Thursday said third-quarter earnings fell as sales of its anti-clotting drug Plavix and other drugs were hurt by competition from cheaper generics.

New York-based Bristol-Myers Squibb (Charts) said it earned $338 million, or 17 cents per share, from continuing operations, compared with $964 million, or 49 cents per share, in the year-ago period.

Excluding special items, the company earned 22 cents per share. Analysts, on average, expected 20 cents, according to Reuters Estimates.

The company's worldwide drug sales fell 17 percent in the third quarter to $3.2 billion. Bristol-Myers blamed part of the decline on the loss of patent protection, in April, of cholesterol-cutting drug Pravachol, which saw a 64 percent plunge, or $192 million, in third-quarter sales.

Sales for Plavix, a blood-thinner and the company's top-selling drug, fell 36 percent to $630 million in the third quarter. This is largely because a rival drugmaker, the privately-owned Canadian company Apotex, temporarily produced generic versions of Plavix without legal clearance until the company was forced to stop.

Sales for Erbitux, a cancer drug that Bristol-Myers markets for the biotech ImClone (up $0.06 to $31.06, Charts), surged 64 percent to $175 million for the quarter.

Bristol-Myers stock edged edged higher, while shares of competitor Merck (Charts) also nudged upward, a day after news that its shingles vaccine Zostavax had picked up a key endorsement from the Advisory Committee on Immunization Practices. Novartis AG (Charts) moved lower in early trading. Novartis on Wednesday learned that the U.S. Food and Drug Administration as approved the company's telbivudine once-a-day drug for treating adults with chronic hepatitis B, a viral infection that attacks the liver.

CNNMoney.com staff contributed to this report.

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