Does my experience in this company helps me in building my career?
It does, I'd consider it fairly equivalent in terms of experience to that of an employee. Your resume should reflect both the consulting firm you were working for and the client firm - and I'll assert that most hiring managers will consider the experience to be from the client firm.
Is there a danger of not getting job as permanent employee to larger firms ?
It may cause you to appear less likely to want to become an employee. Contracting can be a foot in the door, but depending on the position, the firm may prefer a candidate that is an employee from a similar firm.
Don't panic, though. There are a lot of contract positions out there. Contracting is an opportunity to demonstrate the kind of work that you do, and if the firm likes your work, they may offer to convert you to being a full time employee. I know they do, this happened to me, and I've seen it done with others.
If you're worried about what to do next, start fishing for your next position now, don't wait until you're thirsty to dig your well.