Praise be to Allah the Lord of the Worlds.
Sukuk (Islamic bonds) are usually issued in huge amounts. The regulations governing the issuance process are provided in a specific brochure, which also includes the subscription party from where the shares can be bought.
In terms of its legal framing, the subscription party acts as an agent for the issuing party, and its job is to sell the Sukuk. It merely acts as intermediary. Moreover, the special nature of the commercial bank`s work has nothing to do with the ruling of Sharia on buying these bonds through it. From the perspective of Sharia, it is only conditioned that the agent have the capacity and the business is lawful, and both conditions are met by the commercial bank.
In conclusion, it is permissible that the above bank acts as intermediary in buying and selling the Sukuk. And Allah the Almighty knows best.