Influential pension consultant Mercer Investment Management has downgraded its ratings on five Pimco funds, possibly triggering another wave of institutional investor outflows from the Newport Beach, California, bond fund manager.

It was the latest blow after Morningstar downgraded its analyst rating on the flagship Pimco Total Return Fund to "bronze" from "gold" late Monday, citing uncertainty about outflows and the reshuffling of management responsibilities after the exit of co-founder Bill Gross last Friday.

"We have been and will continue to be in close contact with our clients to address their questions. We have long-term and deep relationships with our clients and strong partnerships with consultants around the world, and are confident that the vast majority will continue to stand with us," said a PIMCO spokesperson on the Mercer news.

The Financial Times was first to report that Mercer cut the Pimco Total Return Fund and four other portfolios to a B grade on its A-to-C scale.

Billions of dollars have flowed out of Pacific Investment Management Co, which had $1.97 trillion in assets as of June 30, since the news of Gross's departure sent shock waves through the fixed-income world.

Gross, the bond market's most renowned investor and sometimes called the Bond King, quit Pimco for distant rival Janus Capital Group Inc on Friday, a day before he was expected to be fired from the firm he helped found more than 40 years ago.

The Pimco Total Return and other Pimco funds are widely held in pension systems, university endowments, retail investment accounts and more.

Since the start of the year, investors have pulled $25 billion from the Pimco Total Return Fund, the world's largest bond fund, according to Morningstar data as of the end of August. Its sister exchange-traded fund, the Pimco Total Return exchange-traded fund , saw $448 million in outflows Friday after news of Gross hit, but outflows slowed on Monday to $98 million.

Already a number of institutional investors have placed Pimco on their watch lists, a possible precursor among some investors to pulling funds out of a company. A watch list does not always mean money will be removed from a manager and in some cases is resolved without a change.

The Texas Municipal Retirement System has placed Pimco on its watch list because of Gross's departure, a spokesman said. The system has about $2 billion in a core plus fixed income mandate to Pimco, about 8.51 percent of the total portfolio.

The New Hampshire Retirement System, which does not use a watch list, had already been moving out of Pimco this year as the system overhauls its fixed income strategy, said spokesman Marty Karlon.

The New Hampshire system has about $7.3 billion in total assets, about $200 million of which is invested with Pimco.

"Definitely the news will affect us as we go forward, but nothing's been decided at this point," Karlon said.