A Sam's Club store in Peoria, Illinois.

As small-business owners prepare to comply with health-care rules that require employers offer health insurance, some businesses will have a new option for employees—Sam's Club.

The wholesale retailer—a division of Wal-Mart Stores—this week announced new services for small companies including a private health-care exchange for small-business owners and their workers. The health-care exchange will be offered in partnership with Aetna.