Employers with more than 2,500 workers accounted for the largest mix of voluntary insurance sales in 2011 with almost one-third of total voluntary profit, new research shows.

Findings come from Eastbridge Consulting Group’s second yearly report that examines state-by-state sales and in-force data and provides two measures that relate the data to the number of employed Americans in each state.

The report reveals that estimated sales in 2011 among employers with 2,500-plus employees totaled $1.75 billion. Rounding out the top five largest market segments are employers with 100-499 employees with $1.1 billion; 26-99 employees with $781 million; 1,000-2,500 employees with $662 million and 500-999 employees with $587 million.

Smallest employers attributed the lowest voluntary sales. Employers with 10-25 employees totaled $392 million in sales, while employers with less than 10 employees had $179 million.

Still, Eastbridge president Gil Lowerre says, the sales numbers alone can be deceiving.

“If you look at the ESI (sales divided by the employee population) for each employer size, it becomes clear that some segments are underpenetrated while others are more penetrated,” he says. “Specifically, the very large market (2,500 and over) is underpenetrated even though it accounted for the largest portion of sales given that there was such a significant difference between the sales mix and actual mix of employees for that size.”

The most penetrated market segment for 2011 was the 500-999 segment. While sales were just $587 million, the segment had the highest ESI.

Eastbridge vice president Bonnie Brazzell notes that the percentage of sales coming from any particular segment tends to change a great deal from year to year.

The report is an adjunct to Eastbridge’s annual U.S. Worksite Sales Report.