Pfizer has said that its fourth-quarter profit more than quadrupled, despite competition from generic drugs hurting sales.

The boost came on the back of $4.8 billion gain from selling its nutrition business.

The world's biggest drugmaker said its net income was $6.32 billion, or 85 cents per share, up from $1.44 billion, or 19 cents per share, a year earlier.

Excluding one-time items, the Viagra maker would have had a profit of $3.51 billion, or 47 cents per share - 3 cents more than analysts were expecting.

Revenue fell 7% to $15.1 billion, mainly due to generic competition to cholesterol blockbuster Lipitor. Analysts expected $14.35 billion.