For a foreign investor who has already created a legal structure in Viet Nam and has already been granted an investment certificate, there is no need to create a new company if he wants to undertake a new activity. He can simply request an amendment of the investment certificate.
In order to benefit from this possibility, that was established by the Investment Law of 2005, foreign invested companies created before July 1st, 2006, must re-register under the new regime.
It is also possible to convert the form of incorporation of a company, e.g. from LLC to Joint Stock Company and/or from a 100% owned subsidiary to a joint venture.