Shares awarded with company demerger

Hi, I hold shares as part of my employment compensation in the ultimate parent company which is listed on the US stock market. They recently divested a subsidiary and shareholders were awarded shares in the divested company once it was spun out of the group. I have read HS285 share reorganisations but are you able to confirm that if a UK tax payer holds shares in a US company and is given shares in the company they divest whether this will be treated as a capital gain when the shares that were awarded are sold or if it is treated as income when the shares are awarded at the share price on the date the shares were acquired. At sale I would assume any gain would then be subject to Capital Gains Tax. Thanks for your help.

Hi,
Restricted Stock Units, are a way of employers providing incentives to employees over the long term. When the shares vest your employer should show the income from the vested shares on your P60 after the end of the tax year. You would declare this in the employment section of the tax return. Your employment may hold back some of the shares to pay the tax due.  
To claim a tax credit for the tax paid, means that you should also show the income and tax deducted in the foreign sections. This will allow you to claim a foreign tax credit relief.  
Please have a look at the guidance at:
ERSM20193 - Employment-related securities and options: what are securities: RSUs and dividend equivalents
Thank you.