How do you pronounce designer Nine west in british English?

In British English, "Nine West" is pronounced very similarly to how it's pronounced in American English:

* Nine: The "i" sound is a short "i" as in "pin" or "win"

* West: The "e" sound is a short "e" as in "bet" or "pet". The "w" sound is like the "w" in "water".

So, it would sound something like "nine" - "west".

There's no particular British accent that changes the pronunciation significantly.