Does partial phrase count as infringement?

Sorry to have to break this to you, but if the SM Group Sanctuary Marketing is already registered or even in use, there is no way that you are getting a SM for Group Sanctuary - particularly if you are in the same lanes of commerce. Save yourself a lot of problems and choose another mark. TM infringement is based upon the likelihood of confusion in the marketplace - so if company A has the mark Group Sanctuary Marketing and company B wants to use/get a TM/SM for Group Sanctuary, there would obviously be definite confusion in the marketplace because you are effectively using the same mark, even though you are not using the word "Marketing" with your mark. You have not stated what your services are, but maybe you can use "Group" with something else because "Group" is a very common word so the uniqueness of the word "Group" is not that great. "Sanctuary" is a much rarer word/term, so even if you use some other word with "Sanctuary", you may run into problems. As I said, the best advice? Use another mark. The more fanciful or "made up" a mark is, the more unique and stronger the mark. Think of XEROX or GOOGLE - these words/marks had absolutely no meaning until their respective companies starting using them as TMs.