NEW YORK (Bloomberg) — Tyco International Ltd., the world's biggest maker of security systems, said second-quarter earnings rose and full-year profit will exceed its previous forecast. The ADT alarm business missed some analysts' growth predictions, and shares fell the most in two years.

Profit from continuing operations climbed 66 percent to $273 million, or 56 cents a share, from $164 million, or 33 cents, a year earlier, the Bermuda-based company said in a statement yesterday. Profit excluding some items was 67 cents a share, beating the 58-cent average estimate in a Bloomberg analyst survey.

Chief executive officer Edward Breen wants to improve results by selling slower-growing divisions and by moving plants to lower-cost areas. Sales rose in all five units and operating income rose in four. So-called organic revenue growth at ADT, the largest unit, rose less than some analysts estimated as North American retailer demand and UK commercial activity waned.

"ADT missed our forecast on weaker-than-expected organic growth," wrote Credit Suisse analyst Nicole Parent in a note to investors yesterday. New York-based Parent, who rates the stock "neutral." Total company margins adjusted for some items exceeded her projections.

Revenue in the quarter ended in March rose 8.4 percent to $4.87 billion. Organic growth, or sales increases from businesses Tyco has owned more than a year and excluding translation of currency into US dollars, was 3.6 percent. That was less than Citigroup analyst Jeffrey Sprague's estimate of 5.2 percent.

Tyco now expects full-year profit excluding some items of $2.65 to $2.75 a share, or five cents higher on each end of the range than its January forecast. Analysts, on average, projected 2008 earnings of $2.70 a share.

The company, which got more than half its revenue from outside the US last year, benefited in the quarter from currency translation into US dollars by about $228 million, or 5.1 percent of net revenue, according to the statement.

ADT profit rose 14 percent to $222 million on a four percent increase in sales to $1.97 billion, bolstered by revenue from Asia and Latin America, Tyco said.