BOSTON (AP) — First-quarter earnings at International Business Machines Corp. rose 8 percent and matched Wall Street expectations yesterday, as a boost from software acquisitions helped overcome moderate overall growth.In the first three months of this year, traditionally IBM’s slowest quarter, the Armonk, New York-based company earned $1.84 billion, $1.21 per share. In the comparable period last year IBM showed profits of $1.71 billion, or $1.08 per share.

Analysts surveyed by Thomson Financial were expecting $1.21 a share for the first quarter. IBM’s revenue rose 7 percent to $22.0 billion, slightly ahead of the analyst forecast of $21.9 billion.

“Overall this was a solid quarter,” said Mark Loughridge, IBM’s chief financial officer.

But the real growth in sales was more moderate — 4 percent, if not for weakness in the dollar. Downdrafts in the US currency can inflate the dollar value of deals done in other currencies.

Also of note is that IBM’s weakest geographic segment was its largest and the one closest to home. Revenue in the Americas rose only 1 percent, with the US particularly weak.