Pfizer Inc. on Tuesday reported a 9 percent increase in second-quarter profit, trouncing Wall Street expectations as its revenue jumped sharply due to its mega-acquisition of fellow drugmaker Wyeth last October.

The maker of cholesterol blockbuster Lipitor and impotence pill Viagra said net income rose to $2.48 billion, or 31 cents per share, from $2.26 billion a year earlier. Earnings per share was 34 cents in the year-ago period.

Pfizer, the world's biggest drugmaker by sales, said revenue totaled $17.33 billion, up 58 percent from $10.98 billion in 2009's second quarter.

Excluding one-time items, income was $4.96 billion, or 62 cents a share.

Analysts expected earnings per share of 52 cents on revenue of $16.65 billion, according to a survey by Thomson Reuters.

The company reaffirmed its profit forecast for 2010, saying it expects revenue of $67 billion to $69 billion and earnings per share of 95 cents to $1.10, or $2.10 to $2.20, excluding one-time items. Analysts expect $2.16 per share, on average.

"We continue to make solid progress on the Wyeth integration while we remain focused on delivering strong business performance," Chief Executive Jeff Kindler said in a statement.

Pfizer bought Wyeth for $68 million in a move to diversify the company by adding Wyeth's prized biologic drug operation and successful consumer and animal health divisions.

In premarket trading, Pfizer shares added 2.2 percent to $15.82.