Readers forum: Optical confusion

My client company (A) owns 80 out of the 100 issued shares of B Ltd. The other 20 shares of B Ltd are held by another company (C) which has no connection with company A. All three companies are UK resident trading companies: company B has only one class of ordinary share capital and no other shares in issue. On the face of it companies A and B are in a group relief group and if one makes a trading loss it can be surrendered to the other in the usual way.

However there is an option in place under which A Ltd has granted an option to C Ltd to acquire ten of the shares it holds in B Ltd. Were that option to be exercised A Ltd would hold 70% of B Ltd and C Ltd would hold the other 30%.

My understanding...