A.O. Smith posts higher profit

April 20 (Reuters) - Heater maker A.O. Smith Corp posted a higher quarterly profit, helped by a 10 percent increase in sales of heaters and boilers at its largest North American business, and raised its 2012 earnings forecast.

The company now expects earnings between $2.75 and $2.90 per share from continuing operations for the full year - above its earlier view of $2.65 to $2.85 per share.

A.O. Smith's net earnings from continuing operations almost doubled to $47.5 million, or $1.02 per share, from $24.2 million, or 52 cents, a year ago.