By Chris Dorrell Assets under management (AUM) at Impax Asset Manaegment swelled by nearly five per cent in the first quarter of the year despite the fund reporting outflows. Positive market movements helped the AIM-listed investor, which specialises in environmental and sustainability investments, to grow its AUM by 4.6 per cent in the three months to December. In a statement to the market, the firm reported that total AUM climbed to £39.1bn at 30 December, up from £37.4bn at the end of September. This came despite the firm reporting nearly £1bn in outflows. “Although asset allocation decisio…