Arkx runs the Arkx Clean Energy Fund, which offers investors exposure to the growing clean energy industry through a concentrated portfolio of stocks.
"Ascalon is currently working with Arkx to bring the fund onto various platforms and is also developing a retail version of the product," Ascalon chief executive Andrew Landman said.
The Arkx transaction is Ascalon's second since it was taken over by Westpac.
"With this investment Ascalon will lead the incubation of a new category of boutique investment managers," Landman said.
"The global appeal and higher margin of this asset class combined with Arkx's boutique approach is consistent with Ascalon's growth strategy."
Arkx managing director Geoff Evison said the clean energy sector has a number of long-term growth drivers that offered investors attractive rates of return well into the future.