Millions of workers employed by small businesses are at risk of losing their health insurance coverage due to rapidly rising healthcare premiums charged by insurers.

Insurance costs for large firms will increase 166 percent by 2019, costing these companies $28,530 per employee. Rising costs cut into employee wages, result in less hiring and hurt the competitiveness of U.S. businesses, the report says.

Over the course of this decade, as premiums have accelerated, the percentage of firms offering employees' coverage fell from 69 percent to 60 percent, according to the report.

The news for small business owners is that a growing number of them are unable to provide coverage for employees, in particular those companies with less than 10 workers. Only 46 percent of those companies offer coverage in 2009, a drop from 59 percent in 2000.

Congress is currently locked in a battle over healthcare reform. The Senate has passed two different versions of a bill that need to be assimilated into one piece of legislation.