Impax Asset Management will issue more than 2.6m shares as it completes its takeover of Pax World Management.
Both Pax and Impax are asset management businesses which focus on sustainable investing.
The takeover was initially announced in September 2017 and is due to be completed this week.
In an announcement to the London Stock Exchange this morning (15 January), Impax said the shares being issued are to settle part of the cost of the acquisition of Pax.
When the merger completes, the combined company will have assets under management of £11.5bn.
Last week Impax issued a trading update which revealed its its assets under management, which excludes any impact from the acquisition of Pax, rose by 13 per cent in the three months to the end of December 2017.
Impax, which is listed on the Aim, runs private equity and property funds, as well as traditional equity mandates.