Health insurance giant UnitedHealth Group has agreed to buy healthcare payments company Equian LLC from private equity firm New Mountain Capital for approximately $3.2 billion, according to a Wall Street Journal report.

Based in Indianapolis, Equian processes more than $500 billion in healthcare claims a year for nine of the 10 largest healthcare payers, according to New Mountain. It also analyzes claims both before and after they are paid to find inappropriate or unnecessary bills, as well as to block or recover overpayments.

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Equian was the result of a merger between its predecessor company and Trover Solutions after both were acquired by New Mountain in 2015, according to the WSJ.

The acquisition is the result of a months-long auction process, with Equian likely to be folded into UnitedHealth’s Optum health-services arm – a part of its business that services insurers, hospitals, and other healthcare firms.

With a market value of around $235 billion, UnitedHealth Group is the parent of UnitedHealthcare, the largest health insurer in the US.

“We don’t comment on market rumors and speculation,” a UnitedHealth spokesman told Reuters.