Sales of voluntary worksite benefits increased to $5 billion in 2007, up about 7% from the 2006 total.

Researchers at Eastbridge Consulting Group Inc., Avon, Conn., have reported those figures in the firm’s latest voluntary benefits market review.

Much of the strength in the past 2 years has been due to rebounds at large worksite carriers, such as Aflac Inc., Columbus, Ga., the researchers report.

The average sales increase among the top 15 companies was 10%, the same as in 2006. This year, however, 7 of the top 15 companies reported double-digit sales increases. Just 3 reported decreases, the researchers report.

In-force premiums rose about 6%, to a figure between $15.7 billion and $20.7 billion, the Eastbridge researchers estimate.

More than half of employers now offer at least one voluntary benefit to their employees, the researchers report.