Analysts in a company-supplied poll had forecast net outflows of 1.9 billion pounds.

A shock warning on demand this week from Germany's DWS and cautious outlooks from peers point to a tougher second half for many asset managers, undermined by global trade tensions.

"The first half of 2018 reflected a more challenging operating environment against a more volatile global geopolitical backdrop," Jupiter Chief Executive Maarten Slendebroek said in a statement.

But he told Reuters that trade tensions were not yet having an impact. "There is a bunch of macro events on the horizon - Brexit, trade wars, whatever Trump tweets tomorrow," he added.

Jupiter is preparing for Brexit by setting up a subsidiary in Luxembourg to retain access to Europe's single market.

The unit has hired five key staff, Chief Financial Officer Charlotte Jones said.

Jupiter's assets under management fell 4 percent to 48.2 billion pounds, which this was better than analysts' forecast of a fall to 47.8 billion pounds. Net outflows were partly offset by positive market movements, Jupiter said.

Analysts at KBW highlighted Jupiter's positive investment performance, reiterating their "market perform" rating.

Jupiter's shares rose 2.2 percent to 452.7 pence at 0718 GMT, making it one of the top performers in the FTSE mid-cap index <.FTMC>.

Profit before tax rose 3 percent to 96.5 million pounds, and Jupiter's interim dividend per share increased by 16 percent to 7.9 pence per share, above a forecast 7 pence.

(Reporting by Carolyn Cohn; Editing by Maiya Keidan and Edmund Blair)