Renal Advantage is formed thanks to a divestiture from global dialysis titan DaVita Inc. Looking to avoid anti-trust issues in the wake of its billion-dollar acquisition of Gambro, Inc., DaVita sells 73 clinics to Renal Advantage’s founders for $320.5 million.

The deal is backed by investors at Welsh, Carson, Anderson & Stowe, frequent funders in Nashville’s booming health care landscape.

Three years later, Renal Advantage is the nation’s third-largest for-profit dialysis provider, when it acquires Brentwood-based National Renal Alliance. The company will sell to Fresenius Medical Care for $1.7 billion in 2011.