NASHVILLE (AP) - It's still too early to tell whether an insurance co-op created solely to sell health plans to Tennesseans through the federal government's exchange was able to compete with the state's big insurers.

Community Health Alliance of Tennessee is one of 23 consumer-run co-op insurers created with the help of federal loans to encourage innovation and bring down the costs of insurance. Many of the co-ops have been struggling as consumers picked plans from more established companies.

A spokeswoman for Community Health Alliance said the co-op would not release enrollment figures because it's proprietary information. The co-op had to compete with Blue Cross Blue Shield of Tennessee, Humana and Cigna on the health exchange serving Tennesseans.

Federal reports released so far have not provided enrollment figures for the co-ops.