investing money into another company - is it an expense?

Hi All,

I have a limited company and I'm thinking about setting up another one
which would be doing something completely different. The new company
requires some initial capital which I would like to transfer from my
existing company. What's the best approach from the tax point of view?

a) do I need to take a dividend and pay tax on it, not being able to
claim that amount of money as an expense and then put my personal
money to another company as a director's loan?

OR

b) is there a better option? Ideally I would like to put money from
company A to company B and being able to claim that amount of money as
expense for company A

Please note, I'm 100% shareholder in company A, but I won't be in
company B

Thanks a lot for advice,
Richard