A news release from its Denver world headquarters today announced that DaVita Inc. is selling off its DaVita Medical Group operation for approximately $4.9 billion in cash.

Just last week (Nov. 28), Tacoma’s Northwest Physicians Network was acquired by that same DaVita Medical Group. The local clinic is comprised of more than 1,000 primary care physicians and had operated independently since 1995.

Optum, a health services company component part of UnitedHealth Group in Boston, will acquire the physicians practices aggregated under DaVita Medical Group and merge them with Optum’s primary, specialty, in-home, urgent- and surgery-care delivery network.

A DaVita spokesman refused to provide any further detail about which South Sound operations are included in the firm’s Medical Group. But it is reported that The Everett Clinic, acquired just last year by DaVita for $405 million, will now become part of Optum.

DaVita Medical Group serves approximately 1.7 million patients per year through nearly 300 medical clinics featuring primary and specialist care. It also operates 35 urgent-care centers and six outpatient surgery centers.

Kent Thiry, chairman and CEO of DaVita Inc., said his company plans to use the proceeds from today’s announced transaction for significant stock repurchases over the one to two years following the closing of the transaction, as well as to repay debt and for general corporate purposes.

“Following this transaction, DaVita will continue to be a leader in population health management, with a focus on our U.S. and international kidney care businesses,” Thiry said. “We also expect to pursue other investments in health care services outside of kidney care.”