A Morningstar analyst Friday said it is possible that "hundreds of billions" in assets under management at Pacific Investment Management Co. will follow former chief investment officer Bill Gross to his new post at Janus Capital Group Inc. (JNS).

In a commentary posted on its website, Vincent Lui said the firm has placed Pimco parent company Allianz SE (ALIZF) under review.

"We expect to lower our fair value estimate, as it is likely that ten of billions, if not hundreds of billions in (assets under management) will follow Gross," Mr. Lui said. Results at Allianz, he noted, have been "clearly weighed down" by results at Pimco, adding that "we'd expect to see larger outflows going forward."

Write to Mark Taylor at mark.taylor@wsj.com

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