The cost of homeowners insurance jumped 13 percent last year, with mold being blamed as the leading cause, a consumer group said Monday.

The survey by the Consumer Federation of America reflects the growing problem mold represents for the insurance industry.

Damage from the inky fungus rarely generated insurance claims until a few years ago, when the number of claims exploded in Texas and California, followed by a wave of claims across the country.

Insurers blame the mold complaints for forcing them to raise rates, while industry critics say a primary reason is insurance companies seeing their investment revenue shrivel during a weak economy.

The Consumer Federation surveyed state insurance departments in late 2001 and early 2003 to determine why homeowner's insurance was becoming costly.

Price hikes in 2002 ranged from 4 percent in Oregon to 57 percent in Texas.

Florida mirrored the national average, with a 12 percent increase.

States listed mold as the leading cause for increases, followed by catastrophes, investment income decreases and costly reinsurance.

Eleven states listed mold as a reason for their climbing rates, but Florida was not one of them.

The Sunshine State said natural catastrophes were the main cause of its 12 percent hike.

Still, mold claims have been on the rise in Florida, and the state's insurers say mold has been a primary reason they've raised their rates here, along with sinkhole claims, higher repair costs and reduced investment revenue, said Sam Miller, spokesman for the Florida Insurance Council. The trade group has asked state regulators to exempt insurers from having to cover certain mold damages.

''We're seeing the beginning of that kind of crisis in Florida,'' Miller said, comparing Florida's experience to the first wave of mold claims in California and Texas.

Herald staff writer Douglas Hanks III contributed to this report, which was supplemented with Herald wire services.