PITTSBURGH (AP) — Calgon Carbon Corp. said Wednesday that its second-quarter net income fell 3.6 percent, as higher costs offset sales growth.

The maker of water and air purifying systems earned $10.9 million, or 19 cents per share, down from $11.3 million, or 20 cents per share, in the same quarter last year.

Analysts, on average, expected a profit of 20 cents per share, according to a FactSet poll.

Revenue rose 9.7 percent to $148.4 million from $135.3 million. Analysts expected $147.5 million.

The company said that the effects of unfavorable exchange rates reduced the recent quarter's sales by $3.1 million. Calgon, like other companies that do significant business outside the U.S., can be hurt by a rising dollar because income earned in foreign currencies shrinks when it's translated back into a stronger U.S. dollar.

Activated carbon and service segment revenue rose 4 percent, mainly as a result of higher demand for certain products in the drinking water market and higher pricing on products for the metals recovery market, the company said.

Equipment sales jumped 70 percent on higher revenue recognition from ballast water treatment systems. Consumer sales were flat.

Despite the sales growth, profitability fell, partly as a result of higher coal and plant maintenance costs, the company said.

Calgon said the global economic slowdown, rising raw material and maintenance costs, and delays in implementation of environmental regulations have created a tough business environment. As a result, the company said it has embarked on a program designed to its annual costs by more than $10 million. The company did not release details of the plan.

Calgon shares fell 76 cents, or 5.3 percent, to $13.60 in afternoon trading.