(Adds comment by Macquarie Asset Management, details of SEC's findings, background, paragraphs 2-6)

NEW YORK, Sept 19 (Reuters) - A Macquarie Group investment adviser has agreed to pay $79.8 million to settle charges in connection with overvaluing collateralized mortgage obligations $(CMO)$ held in advisory accounts, the U.S. Securities and Exchange Commission said.

The regulator found that Macquarie Investment Management Business Trust, which is a part of Macquarie Asset Management, overvalued about 4,900 largely illiquid CMOs in 20 advisory accounts, including 11 retail funds and also executed hundreds of cross trades that favored certain clients over others.

From January 2017 through April 2021, the firm, which managed a fixed-income investment strategy primarily focused on mortgage-backed securities, CMOs and Treasury futures, assigned the wrong prices to certain products and thus overstated the performance of client accounts, the SEC said.

Regulators found Macquarie attempted to minimize losses to redeeming investors by arranging cross trades with affiliated accounts, rather than selling the overvalued products into the market.

Macquarie Asset Management, which did not admit or deny the SEC's findings, said in a statement it has already begun remediation and is continuing the process, with the focus on clients.

“Our business is built on the principles of integrity and accountability," the statement said. "This legacy matter is not consistent with how we do business."

(Reporting by Chris Prentice in New York Editing by Matthew Lewis)

((christine.prentice@thomsonreuters.com; +1 (202) 843-6464;))