Dialysis giant DaVita Inc. today announced that it is buying Nashville’s DSI Renal for $690 million.

DSI runs 106 dialysis centers serving about 8,000 patients. Its current annual revenue is approximately $360 million. Denver-based DaVita (Ticker: DVA) is the country's second-largest dialysis firm, operating nearly 1,600 clinics with annual sales of $6.1 billion.

“This acquisition introduces us to several new geographies and makes us a more effective competitor in selected areas” said DaVita Chairman and CEO Ken Thiry. “We will be able to bring the broader line of DaVita chronic kidney disease services to DSI patients. These services will be beneficial for patients, physicians, payors and taxpayers in providing more effective care and helping to reduce costs to the health care system.”

The deal is expected to close in the third quarter of this year, pending antitrust approval, which DaVita expects will require some divestitures. It is not yet clear what DaVita plans to do with DSI’s local corporate presence; a spokesman did not immediately return a call seeking comment Friday.

Investors should expect the deal to be "very accretive," according to Stephens Inc. analyst Andreas Dirnagl. He said in a research note this morning that DSI will add 35 cents per share to DaVita's annual earnings.

Dirnagl also noted that the timing of the deal — within weeks of the implementation of a new bundled payment system for dialysis providers — is telling.

"Despite what DVA management may say about the DSI deal not being an indication of its outlook for the bundle, we would put forward that spending $700 million and acquiring 8,000 patients in the current environment can certainly be read as a sign that management is comfortable with its positioning in the bundle," he wrote. “We continue to believe that the bundle will prove to be a long term positive for DVA and the dialysis industry."

Today’s transaction is the second major local dialysis deal in recent months. Brentwood-based Renal Advantage folded into Washington-based Liberty Dialysis in November, creating the country's third-largest dialysis provider in a deal valued at about $600 million.

DaVita's stock is up more than 2 percent on today's news.