The flood of money out of Pimco's flagship Total Return fund slowed in May to its lowest level since last fall’s departure of star manager Bill Gross, people familiar with the matter said.

Investors pulled about $3 billion in assets from the $110.4 billion bond fund last month, these people said. It was the fifth successive month that outflows dropped, according to fund-research firm Morningstar, and the amount was the smallest since Gross exited abruptly last September.