BOSTON — Massachusetts has fined more than a thousand companies over $18 million for failing to offer medical insurance to their workers – a precursor of what some business owners fear could happen on a national scale if President Obama signs a sweeping health care overhaul.

The fines are for violating a provision in Massachusetts’ landmark 2006 health care law that requires larger companies to offer insurance or pay an annual fine of $295 per full-time employee.

In 2008, 807 of 23,128 eligible Massachusetts firms were found liable for the fine, known under the law as the “fare share contribution.” They were on the hook for a total of $8.6 million, or an average of $10,663 per employer. In 2007, 1,045 firms were found liable for $10.5 million, or an average of $10,047 each. Statistics for 2009 were not yet available.

The Massachusetts law has been used as a blueprint for a national health care bill heading to a critical vote in the U.S. House.

Like the Massachusetts law, the federal legislation includes penalties for businesses that don’t comply. While the federal bill would not require coverage as Massachusetts does, it hits employers with a $2,000-per-employee fee if the government subsidizes their workers’ coverage.