TUCSON, Ariz. (AP) - A California company has acquired all three Tucson Occupational Medicine healthcare centers.

Valencia, Calif.-based U.S. HealthWorks says the acquisition announced Monday expands its medical center numbers nationwide to 131, including six in Arizona.

The terms of the transaction were not disclosed. The acquisition went into effect Friday.

U.S. Healthworks says the latest three centers diagnose and treat injuries and illnesses as well as provide preventive services, exams and testing and return-to-work programs.