May 12 (Reuters) - A union health benefits fund has sued

top U.S. dialysis service providers DaVita ( DVA ) and Fresenius

Medical Care in federal court in Colorado for

allegedly conspiring to artificially inflate treatment costs by

billions of dollars.

The proposed nationwide class action was filed on Friday by

Pennsylvania-based United Food and Commercial Workers Local

1776, which provides benefits for thousands of members across

the United States.

DaVita ( DVA ) and Fresenius, the two largest dialysis providers in

the United States, illegally carved up areas in the country to

avoid competition, the lawsuit said.

The plaintiffs also said the companies since at least 2021

have engaged in parallel price increases that are higher than

competitors and "not adequately explained by market forces."

DaVita ( DVA ) in a statement on Monday said "the allegations in

this case are baseless, and we will defend against it

vigorously."

Fresenius declined to comment. Attorneys for United Food and

Commercial Workers Local 1776 did not immediately respond to

requests for comment.

German healthcare group Fresenius spun off Fresenius Medical

Care in 2023 and is not a defendant.

In the United States, DaVita ( DVA ) and Fresenius earn more than

90% of industry revenue for dialysis services, according to the

lawsuit. The complaint said the two companies acquired their

dominance through a "decades-long strategy of acquiring small,

independent clinics in uncontested mergers."

The lawsuit also alleged the two companies have had

opportunities to collude on pricing through their partnerships

and deals.

United Food and Commercial Workers Local 1776 pays for

dialysis services for its members. The lawsuit seeks class

status for all purchasers of outpatient dialysis services from

DaVita ( DVA ), Fresenius or one of their affiliates.

DaVita ( DVA ) is among a group of outpatient medical center

operators facing antitrust claims in the federal court in

Chicago, Illinois, over employee compensation and mobility.

The plaintiffs in that proposed class action, filed in 2021,

have alleged a conspiracy over hiring and recruitment practices

for senior employees at ambulatory surgery centers and

outpatient medical facilities suppressed pay.

An expert for the plaintiffs has estimated class-wide

damages of nearly $870 million in that case. DaVita ( DVA ) and the

other defendants in that lawsuit have denied any wrongdoing.

The case is United Food and Commercial Workers Local 1776

and Participating Employers Health and Welfare Fund v. DaVita

Inc ( DVA ) et al, U.S. District Court, District of Colorado, No.

1:25-cv-01478.

For plaintiffs: Stephen Tillery and Andrew Ellis of Korein

Tillery, Vincent Briganti of Lowey Dannenberg and Eric Young of

Young Law Group

For defendants: No appearance yet

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