About 2,400 workers at one of the nation's largest lab testing companies will become employees of UnitedHealth Group's Optum division under a partnership agreement announced Tuesday.

Workers in the revenue management department at New Jersey-based Quest Diagnostics would join Optum's division for "revenue cycle management," which assists health care providers with collecting medical bills.

The 10-year deal will increase by about 20 percent the value of billing transactions processed by Optum. Currently, the company said it processes about $50 billion annually on behalf of health care providers.

None of the Quest jobs are slated to move to Minnesota, an Optum spokesman said.

Quest Diagnostics, in turn, would become Optum's primary vendor for certain screening tests in employer health plans. The companies also would work to increase the use of diagnostic information services to boost health care efficiency.

Financial terms were not disclosed.

Minnetonka-based UnitedHealth Group includes UnitedHealthcare, which is the nation's largest health insurer, and Optum, the Eden Prairie-based division for health services and information technology. Optum's revenue cycle management business has been growing in recent years, including a vendor agreement with Mayo Clinic.

Christopher Snowbeck • 612-673-4744

Twitter: @chrissnowbeck