Morningstar said it has place all the rated funds of Pacific Investment Management Co. under review following the resignation of managing director Bill Gross, the firm said Friday on its website.

The action includes Pimco's flagship Total Return Fund, Morningstar said.

Morningstar added that the "depth of resources" at Pimco "means investors have time to reassess their options."

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

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