I.B.M. reported quarterly earnings and revenue yesterday that surpassed Wall Street estimates, with profit rising 12 percent on strong growth in software and services and renewed vigor in the American market.

The company’s performance shows that International Business Machines is making progress in its shift toward selling higher-margin software and services and that corporate spending remains strong.

“This was a really strong quarter, close to firing on all cylinders,” Mark Loughridge, I.B.M.’s chief financial officer, told analysts in a conference call.

As both the largest information technology services company and a major supplier of software and hardware to large corporations, I.B.M. serves as a bellwether for the overall strength of the corporate computing market.

The company reported earnings of $1.55 a share, including 5 cents a share relating to the sale of its printing division, for a pretax gain of $81 million. Without the gain from the sale, I.B.M.’s earnings were $1.50 a share, surpassing analysts’ forecast of $1.47 a share.

The earnings represent a 15 percent increase from $1.30 a share in the second quarter last year, making the second-quarter performance I.B.M.’s best for quarterly revenue growth since 2001, said Samuel J. Palmisano, the company’s chairman, president and chief executive.

Revenue for the second quarter increased 9 percent, to $23.8 billion, from $21.89 billion, beating analysts’ forecast of $23.1 billion. Some of the strength, I.B.M. executives said, was a result of the dollar’s weakness: when adjusted for currency changes, I.B.M.’s revenue grew 6 percent.

“Revenue growth across the board was strong,” said A. M. Sacconaghi an analyst with Bernstein Research. “It was a combination of a modestly better market and better execution by I.B.M.”

Second-quarter profit, including the gain from the printer division, rose to $2.26 billion, from $2.02 billion a year earlier.

Mr. Loughridge raised guidance slightly for 2007, saying he expected earnings growth of 14 percent to 15 percent, rather than his previous forecast of 13 percent to 14 percent.

Investors applauded the report, sending shares up more than 3 percent, to $114.85, in after-hours trading. The company’s shares closed the regular trading session at $111.08, up 31 cents a share.

“It’s been a long time since the stars have been so aligned for all three business units at I.B.M.,” said David M. Grossman, an analyst at Thomas Weisel in San Francisco.

Profit margins at I.B.M. have been consistently improving. Last year, the company reported record earnings, and in the second quarter, overall profit margins increased slightly, to 41.8 percent.

But in the first quarter, the company recorded a sharp drop in sales in the United States, particularly to large corporations. That trend reversed itself during the second quarter, when I.B.M. reported that revenue in the Americas, which includes the United States, Canada and South America, grew 6 percent, to $10.1 billion.

“This shows that the U.S. technology market seems to be healthy and stable with a good demand trend,” Mr. Grossman said.

Revenue in Europe and the Middle East rose 13 percent, to $8.2 billion, while sales in the Asia-Pacific region increased 10 percent, to $4.6 billion.

I.B.M. software’s revenue showed the biggest gain, growing 13 percent, to $4.8 billion, in the second quarter, while revenue in the hardware division rose 2 percent, to $5.1 billion.

“Software is now the largest provider of I.B.M. profit, and our most stable source of growth,” Mr. Loughridge said.

Services revenue booked during the quarter increased 10 percent, to $8.76 billion. New service contracts, which are generally seen as good indicators of future growth, also showed marked improvement. I.B.M.’s services division signed $11.7 billion in contracts during the second quarter, up from $9.6 billion a year ago.