CIBC Asset Management Inc. Thursday announced portfolio sub-advisor changes. As part of the changes, American Century Investment Management, Inc. will be added as a sub-advisor to certain Imperial pools and funds.

Headquartered in Kansas City, Mo., the firm manages approximately $121 billion in assets. In August 2011, CIBC acquired a minority ownership position in American Century.

“The experienced investment teams at American Century will add diversification of market capitalization and investment style to these investment pools and funds,” said Steve Geist, president of CIBC Asset Management, in a release.

Imperial U.S. Equity Pool

American Century will continue to serve as a portfolio sub-advisor for components of the Imperial U.S. Equity Pool, with an increased allocation to both the U.S. all-cap growth and U.S. all-cap value components of the Pool.CIBC Global Asset Management Inc., Metropolitan West Capital Management, LLC, Aletheia Research and Management, Inc. and Fiduciary Management Inc. will continue to serve as portfolio sub-advisors for other components of the pool.

Imperial Overseas Equity Pool

American Century has been appointed as an additional portfolio sub-advisor for the Imperial Overseas Equity Pool, managing the international all-cap growth component of the Pool. Causeway Capital Management LLC, Pictet Asset Management Limited and Pyramis Global Advisors, LLC will continue to serve as portfolio sub-advisors for other components of the pool.

Imperial International Equity Pool

American Century has been appointed as an additional portfolio sub-advisor for the Imperial International Equity Pool, managing the international all-cap growth component of the Pool. Causeway Capital Management LLC, CIBC Global Asset Management Inc., Pictet Asset Management Limited and Pyramis Global Advisors, LLC will continue to serve as portfolio sub-advisors for other components of the pool.

Renaissance Canadian Balanced Fund and CIBC Balanced Fund

American Century has been appointed as a portfolio sub-advisor for the Renaissance Canadian Balanced Fund and CIBC Balanced Fund, managing the global component of the funds. CIBC Global Asset Management Inc. will continue to serve as portfolio sub-advisor for the domestic portion of the funds.

All changes take effect July 1.