Bill Gross’s Pimco Total Return Fund, the world’s biggest mutual fund, had its fifth straight month of withdrawals in September.

Clients pulled an estimated $5.4 billion from Pacific Investment Management Co.’s Total Return Fund, leaving the fund with assets of $250 billion at the end of last month, Chicago- based research firm Morningstar Inc. said today in an e-mailed statement. Jeffrey Gundlach’s DoubleLine Total Return Bond Fund had $2.1 billion of net redemptions in September, its biggest monthly total ever, Morningstar said yesterday.

Fixed-income withdrawals were triggered by U.S. Federal Reserve Chairman Ben Bernanke, who told Congress on May 22 that the central bank could start reducing its bond purchases and is prepared to begin phasing out its unprecedented easing program later this year. The Fed unexpectedly refrained from tapering its $85 billion in monthly bond purchases at the Sept. 17-18 policy meeting, saying it needs more evidence of lasting improvement in the economy.

Investors pulled about $121 billion from U.S. bond funds from May 31 through Sept. 18, according to estimates from the Investment Company Institute. The funds attracted $1.3 billion in the week ended Sept. 25.

“While core bond categories have experienced outflows industrywide, we have continued to see inflows into absolute return and unconstrained strategies,” Mark Porterfield, a spokesman for Pimco, said in an e-mailed statement.

Pimco’s Returns

Pimco Total Return returned 1.7 percent in the past month, beating 98 percent of peers, according to data compiled by Bloomberg. The fund declined 2 percent this year, putting it behind 54 percent of similarly managed funds, the data show. Over the past five years, it has returned an average of 7.9 percent, ahead of 89 percent of rivals.

“Typically it’s a one- to two-month lag in which investors see their statement or advisers see their statement and they recognize the recent performance of the Total Return Fund and they say, ‘OK, the bleeding has stopped and now we can make some money,’” Gross said during a Bloomberg Radio interview Sept. 19.

Pimco, based in Newport Beach, California, is a unit of Munich-based insurer Allianz SE. The firm had about $1.97 trillion in assets as of June 30.

Morningstar estimates deposits or withdrawals for mutual funds by computing the change in assets on a monthly basis that isn’t accounted for by performance. The fund’s actual withdrawals or deposits may differ from Morningstar’s estimates because of the timing of purchases and redemptions or dividend distributions.