Pfizer Inc
posted fourth-quarter earnings slightly below analysts' expectations and gave a disappointing forecast for 2010 and 2012, sending its shares down nearly 3 percent.

The world's biggest drugmaker said on Wednesday that quarterly profit rose to $767 million, or 10 cents per share, from $266 million, or 4 cents per share, a year earlier.

Excluding special items, Pfizer earned 49 cents per share. Analysts on average had expected 50 cents, according to Thomson Reuters I/B/E/S.

Revenue rose 34 percent to $16.5 billion, above Wall Street expectations of $15.9 billion.

Pfizer, which completed its $67 billion purchase of Wyeth in October, said the results included 2.5 months of the acquisition's sales in the United States and 1.5 months from overseas.

Pfizer forecast full-year 2010 earnings of $2.10 to $2.20 per share. Analysts on average had expected $2.27, according to Thomson Reuters I/B/E/S.

The company said the strengthening dollar, which reduces the value of overseas sales, would crimp earnings this year 6 cents per share more than it had expected.

Pfizer said it expected revenue this year of $67 billion to $69 billion, roughly in line with Wall Street's forecast of $67.5 billion.

But the company cut its 2012 revenue outlook to between $66 billion and $68.5 billion, from an earlier forecast of $70 billion provided a year ago.

Pfizer said it trimmed the forecast because it has sold off about half of Wyeth's Fort Dodge U.S. animal health business, folded Pfizer's HIV drug business into a venture with GlaxoSmithKline and returned Wyeth's rights to a constipation drug being developed by Progenics Pharmaceuticals Inc

In view of the lowered revenue projection, Pfizer said it was cutting its 2012 profit outlook to between $2.25 and $2.35 per share, excluding special items. A year ago, it had forecast $2.42 per share.

Shares of Pfizer were down 2.7 percent at $18.72 in trading before the market opened.

(Reporting by Ransdell Pierson and Lewis Krauskopf, editing by Gerald E. McCormick and Lisa Von Ahn)