IBM Corp.'s first-quarter net income grew 7 percent, helped by strong profit margins in its services business and strong revenue growth across its software and services businesses.

IBM said Tuesday that it earned $3.07 billion, or $2.61 per share, in the January-March period. That's up from $2.86 billion, or $2.31 per share, a year earlier.

Excluding special items such as acquisition costs, IBM earned $2.78 per share in the latest period.

Revenue was flat at $24.7 billion, falling short of analysts' expectations. Software and services revenue grew, but IBM's hardware and financing segments saw a decline.

Analysts surveyed by FactSet, on average, had expected adjusted earnings of $2.66 per share on revenue of $24.82 billion.

IBM, which is based in Armonk, N.Y., also said it is raising its full-year guidance. It now expects adjusted earnings of at least $15 per share. That's up from its earlier outlook of at least $14.85 per share. Analysts were expecting $14.93 per share.

IBM's long-term goal is to reach at least $20 per share in adjusted earnings by the end of 2015.

IBM's stock fell $3.95, or 1.9 percent, to $203.50 in after-hours trading Tuesday. During the regular session, the stock gained $4.73, or 2.3 percent, to close at $207.45.