Pfizer on Tuesday reported better-than-expected fourth-quarter results, helped by rebounding sales in emerging markets, but the drugmaker forecast 2013 profit weaker than Wall Street estimated.

Pfizer, the largest U.S. drugmaker, said quarterly earnings quadrupled to $6.32 billion, or 86 cents per share, as it recorded a gain from selling its nutritional products business to Swiss food groups Nestle for about $12 billion in November.

In the year-earlier quarter, it posted a profit of $1.44 billion, or 19 cents per share.

Excluding special items, Pfizer earned 47 cents per share in the quarter. Analysts, on average, expected 44 cents per share, according to Thomson Reuters I/B/E/S.

Global company sales fell 7% to $15.1 billion, hurt by generic competition for its Lipitor cholesterol fighter, but came in well above expectations of $14.37 billion.

Pfizer forecast full-year 2013 earnings of $2.20 to $2.30 per share, excluding special items. The average analyst estimate was $2.29 per share, according to Thomson Reuters.

"Pfizer's 2013 forecast is a little lighter than expected, but won't cause me to lose sleep," said Judson Clark, an analyst with Edward Jones. He said he has a "buy" rating on the shares because of its strong pipeline of experimental drugs.

Clark said the company's forecast would have been 2 cents per share higher if not for interest expenses associated with a planned spinoff of its animal health business into a new company called Zoetis.

Company sales in emerging markets rose 17% to $2.65 billion, in contrast with a slight decline in the prior quarter.

Global Lipitor sales fell 71% in the quarter to $584 million, but that was offset by strong sales of other medicines.

Sales of its Prevnar vaccine against pneumococcal bacteria jumped 19% to $993 million, helping ease concerns about weak sales in earlier quarters. Sales of Celebrex, used to ease pain from arthritis, rose 12% to $750 million.