Legal & General Investment Management's assets under management grew 11.8% over the six months ended June 30 to £1.135 trillion ($1.38 trillion).
The firm in a financial update Wednesday credited much of the increase to £37 billion in passive flows coming from Japan's ¥159.2 trillion ($1.49 trillion) Government Pension Investment Fund.
Legal & General Group, the money manager's parent company, recorded external net inflows of £60.3 billion in the six months, compared with £14.6 billion in net inflows for six months ended June 30, 2018, according to the update.
AUM from international clients increased 32.9% for the six-month period to £343 billion, up from £258 billion on Dec. 31 and £229.3 billion from a year earlier.
Net inflows across the international business totaled £44.6 billion for the six months, compared with £9.9 billion for the six months ended June. 30, 2018.
In the six-month period, LGIM also saw net inflows of £2.6 billion from the U.S. and £4.9 billion from Europe, excluding assets gained when GPIF, the Tokyo-based pension fund, hired LGIM as passive manager of foreign equities in March.
LGIM recorded £10.7 billion of net inflows in its U.K. institutional business.
LGIM's defined contribution business attracted net inflows of £3.6 billion for the six-month period, boosting AUM 35% to £86.4 billion, compared with £71 billion as of Dec. 31 and £64 billion as of June. 30, 2018.
Retail strategies saw inflows of £1.7 billion.
CEO Michelle Scrimgeour called it "a good first half of the year for LGIM. ...We have continued to make great strides in growing our international business and have had some significant wins, not least securing the mandate with the Japan Government Pension Investment Fund."
She added: "At the same time, we have invested in improving our operating platform and continue to invest in enhancing customers' digital experience. That work continues apace."