HI
I do not think this is possible with the core profile system but many third party modules cover this common need well.

I personally use the UCanUse User attributes module. It lets me have multiple registration forms and comes with a replacement for the USER skin object so that the user is directed to the right profile form.

It has some nice features like being able to split profile pages into sections as slave modules and the next version has tokenised layouts if needed. 

I  think that when you need to do this kind of thing it pays to put in a module that can grow with you a little as there are often other things its useful to be able to do with multiple types of membership such as which page are different users redirected to on login.

The Ucanuse module is complex but there are now setup wizards and support is very good.

Ian