(Fixes pronoun in paragraph 7)
By Jennifer Ablan
NEW YORK, Feb 1 (Reuters) - The DoubleLine Total Return Bond Fund posted an estimated net outflow of $1 billion in January, its third straight net cash withdrawal after it bled $3.5 billion the previous month, data from research firm Morningstar showed on Wednesday.
The fund, which launched in April 2010 and is DoubleLine's flagship, attracted a net $3.05 billion in new cash for all of 2016, the Morningstar data showed.
Overall, DoubleLine's U.S. open-end mutual funds saw outflows of $190 million for January, Morningstar said.
The DoubleLine Total Return Bond Fund invests primarily in mortgage-backed securities and is run by DoubleLine Chief Executive Jeffrey Gundlach and the firm's president, Philip Barach. Gundlach is known on Wall Street as the 'Bond King.'
While investors pulled cash from the firm's flagship fund, the DoubleLine Shiller Enhanced CAPE fund and DoubleLine Flexible Income Fund were two of the firm's funds that attracted new money in January - $234 million and $108 million, respectively.
DoubleLine analyst Loren Fleckenstein said the Morningstar estimates worked "pretty well" for individual funds for multiple-month periods and for fund categories for individual months but they could sometimes be "off" when dealing with a single fund for a single month.
"It's just a limitation of their estimate methodology," he said in a telephone interview.
Fleckenstein said that Morningstar's estimate for January overestimated DoubleLine Total Return's net outflow by $200 million and overestimated the Flexible Income's net inflow by about $30 million.
(Reporting by Jennifer Ablan; Editing by Andrew Hay)