It's an Alpinestars CTM 400 from 2001 I think.
I've never seen another one and I found it on ebay by chance. There seems to have been a few Alpinestars bikes sold in Europe (Spain mostly) that didn't get anywhere else. I know very little about them except what I could make out from this website which use to sell them..
http://www.bikezona.com/bicicletas/todo ... sp?id=3742
Apart from sharing the name i am not sure if they are anything to do with the original Alpinestars MTB brand.
I tried to get an idea for the build from the pics on the site above but it's currently a bit of a dogs dinner as i couldn't be bothered to spend too much on it (I was doing the Lemond at the time) , hope to get it working though as it's incredibly light and quite cool looking I think..
MTB - 1989 Ritchey Ultra , 1990 Explosif, 2001 Santa Cruz Superlight
Road - 1984 Koga Miyata Gents Racer, 2009 Pegoretti Duende
Wanted - 1" black quill stem with cable stop.
'It doesn't get easier, it just gets faster' - G Lemond " Everything in life's a race mate" - G Farmer