Envision Healthcare Holdings Inc. and Amsurg Corp., both providers of physician and other healthcare services, are in talks to merge to form a company with a combined value of more than $9 billion, reports the Wall Street Journal.

The companies are reportedly in advanced discussions, but it has not been announced how the deal would be structured or if the deal will be finalized.  

AmSurg provides outsourced physician services to more the 450 facilities across 29 states, ambulatory surgery, contains 250 facilities that perform procedures that don’t require an overnight stay, and employs more than 5,000 doctors and other healthcare professionals in 38 states.

Envision also provides physician services such as emergency care, anesthesiology and surgery, in addition to ambulance and other medical-transportation services. The company previously bought the privately held ambulance and fire-protection company Rural/Metro Corp. for $620 million. Envisons' EmCare brand has more than 13,000 physicians and its AMR brand contains more than 20,000 paramedics and emergency medical technicians.

Envision has a market value of $4.8 billion while AmSurg is valued at $4.3 billion.