An exemption (also called SSE) from corporation tax on chargeable gains for certain share disposals by companies. The shares being disposed of must represent at least a 10% stake in the company, they must have been held for at least a year and the company must be trading (or be the holding company of a trading group).
These conditions are relaxed for institutional investors. The exemption does not apply to individuals or other non-corporates. It applies automatically, without the need for a claim and it is not limited to disposals of shares in UK resident companies.