Colorado-based Envision Healthcare Holdings and AmSurg, headquartered in Nashville, have agreed to become one company.

The merger creates a new company worth about $10 billion.

The two healthcare service providers signed a merger agreement to combine their stock at a fixed exchange ratio of 0.334 AmSurg shares per Envision share, the companies announced on June 16.

Envision shareholders will own approximately 53 percent, and AmSurg shareholders will own approximately 47 percent of the combined organization.

The boards of directors of both companies approved the merger.

[See also: Running list: Health IT mergers and acquisitions.]

The combined company, named Envision Healthcare Corporation, will be co-headquartered in Nashville, and Greenwood Village, Colorado.

Together, the companies offer an array of clinical network products, including outsourced physician services in emergency, hospital, anesthesia, radiology and children’s departments. They also provide tools for ambulatory surgery, post-acute care and medical transportation.

Once the merger is complete, Christopher A. Holden will lead the combined company as president and CEO, the same positions he holds at Amsurg. William A. Sanger, who serves as president, CEO and chairman of the board of Envision, will take the role of executive chairman of the board of the combine company.

“At Envision, we have been actively advancing our integrated delivery and market-centric strategies while Amsurg has been diversifying and building its national presence,” Sanger said in a statement. “Our two organizations complement each other in a way few others could, and this merger will accelerate our collective ability to positively impact healthcare delivery across the country.”