Four additional Utah companies, including R.C. Willey Home Furnishings, have signed up to participate in a pilot project that the Utah Health Exchange has designed to help it address the future insurance needs of the state's largest employers.

The Legislature created the Utah Health Exchange, an online health insurance marketplace. It represents an attempt by state lawmakers to increase Utahns' access to health insurance and rein in rising premiums for businesses.

Initially designed to address the needs of small business, the exchange got off to a wobbly start in August has been plagued by low participation and higher-than-expected premiums. It opened up a pilot program for a limited number of bigger employers in February on the hope such companies will help drive down premiums.

Originally, large employers were not going to be able to join until 2012, said Dan Schuyler, an exchange spokesman. But the Legislature changed the law so that large companies could begin to participate beginning in the first quarter of next year.

In order to prepare for what it hopes will be a flood of large businesses utilizing its online marketplace, the Exchange set up a pilot program to help it work out the logistics.

"There are different eligibility requirements for large and small businesses," Schuyler said. "It is important for us to make sure we have the processes in place to handle both."

And as part of that effort, three entities -- Zions Bank, the Provo-based APX Alarm, Health Equity, a Salt Lake health care financial services firm and the city of Spanish Fork -- came on board to help the health exchange work out the kinks.

They have now been joined by R.C. Willey; Mediconnect Global, a South Jordan-based medical records retrieval service; Blendtec, a producer of blenders and mixers; and Prosper Inc., a company that provides coaching and mentoring to people interested in starting a home-based business.

"Like any business we're interested in exploring opportunities to reduce or minimize our medical insurance costs," said Greg Sorensen, human resources director for R.C. Willey, which claims approximately 2,500 employees in four western states. "Joining the pilot program will give us an opportunity to see what makes sense for the company and our employees."

Schuyler said the eight companies that are involved in the pilot project bring 40,000 to 50,000 members to the exchange.

It is designed to offer a way for companies to pay a fixed amount toward their employees' medical coverage, instead of buying the coverage directly for them. Their workers then can shop for a plan on the exchange. If it costs more than the employer kicks in, the workers pays the difference using pretax dollars.