The AIM-listed company, which invests in projects focused on the transition to a more sustainable global economy, saw its assets under management (AUM) rise to a total of £15.7bn in the two months to 30 November, thanks to net inflows of £500mln.
In the new financial year, Impax said it is planning to make further investments in the renewable energy sphere.
The group's year ended 30 September 2019 saw a 29% jump in pre-tax profit to £18.9mln compared to 2018, while AUM increased by 21% to £15.1bn. Revenue was up 12% to £73.7mln and net cash at the end of the period was £11.9mln.
The company said its management has planned a new dividend policy whereby the annual payment will be within a range of 55% and 80% of adjusted profit after tax, to be approved by and paid to shareholders next March.
The recommended full-year payout for now is 4p, to rise to 5.5p if the new policy is approved, representing a 34% increase from last year.
“We have a strong pipeline in place for 2020. The drivers behind the global economy's transition to a more sustainable model are only increasing and we remain ideally positioned to benefit from this,” Impax chief executive Ian Simm said in its statement.
“The solid foundations we've laid down over the last twenty years and the investments we have made in our business should support significant further growth for the company,” he added.