Something, nothing?

Mr A and Mr B are members of a limited liability partnership (LLP) which was established to undertake a property deal. The only substantial asset of the LLP is land which cost £100 000 (funded by capital contributed by the members) but which is now worth £400 000.

For various reasons Mr A now wishes to withdraw from the project and he has found Mr C (not connected with Mr A or Mr B) who is willing to purchase Mr A’s interest in the LLP for £200 000.

My question is what is the tax treatment of the ‘profit’ of £150 000?

In substance the full £200 000 is a payment for an interest in stock which cost £50 000: so is this profit taxed as income in Mr A’s hands?

If so does it increase the tax-deductible cost of stock in the LLP? And...