First-quarter profit grew at

Internet Security Systems

(ISSX)

as revenue increased 15%.

The company's shares climbed in after-hours trading, gaining 2.2% to $18.05.

The company said after the bell Wednesday that net income for the quarter ended March 31 rose to $7.85 million, or 16 cents a share, from $5.22 million a year earlier.

Excluding items in both periods, profit rose to $9.02 million, or 19 cents a share, from $6.35 million, or 13 cents a share. On that basis, a Thomson First Call survey of analysts had expected, on average, earnings of 18 cents a share.

Revenue in the first quarter grew to $76.8 million from $67.1 million. Analysts were expecting $77.8 million in the latest quarter.

Looking ahead, ISS said it expects second-quarter revenue of $78 million to $82 million and earnings of 16 cents to 19 cents a share, with earnings before items of 19 cents to 21 cents a share.

Analysts were expecting second-quarter earnings before items of 20 cents a share on revenue of $80.2 million.

For the full year, ISS anticipates revenue of $325 million to $335 million and earnings of 69 cents to 75 cents a share. Earnings before items are expected to be 79 cents to 85 cents a share.

Analysts were expecting full-year earnings before items of 83 cents a share on revenue of $331.4 million.