I am intending to pursue a PhD in Computational Finance (preferably for CMU). But suppose after two years i feel that i am really not available for a long commitment of five years, can i at that point leave with a MS degree in computational finance (of course after completing the course requirement for the same) from the same university.Also can somebody enlighten me on the career prospects, in the industry ,after a PhD in computational finance, as i am not interested in joining academics.

I don't see why they would'nt award you a MS. Within the first couple of years you'll probably be done with your coursework & qualifiers. But, BUT, should your boss sense that you joined simply to weather a market downturn (and I'm not saying thats the case here), and if he's really really pissed off......watch it!! Typically, when you enter a PhD program your boss has probably earmarked funds for your stay there. And, dropping off midway is disruptive, financially & researchwise ...... not to mention that some other candidate was deprived of an opportunity. On a separate note, if one doesn't perform too well, and are asked to leave, they also tend to hand you a MS.

I would strongly advise you check with the school first. Often you can apply for a Msc and then when you complete that apply into the Phd program. Going the otherway often doesn't work as the schools want to discourage people from dropping out of the Phd program.s

You can also have a look at the following thread where very similar questions were asked:M.S. is contained in PHD??