To come to the UK as an overseas parent company's sole representative you must be a senior employee (but not a majority shareholder in the company) who intends to establish a commercial presence for the company in the UK. This may be a registered branch or a wholly owned subsidiary concerned with the same type of business activity as the parent company.
The company must have no branch, subsidiary or other representative in the UK. If the company has a legal entity in the UK but this does not employ staff or transact business you may still be able to come here as its sole representative. You must also be able to demonstrate your English language ability.