Does changing domain name hurts search engine ranking and page rank?

My blog has .INFO TLD. It's about 3 year old. I recently got .COM TLD for the same domain.

Now, my question is: does changing domain name from example.info to example.com hurts my ranking and pagerank? By changing TLD do I lose all the backlinks I got for .INFO TLD?

I have been redirecting .COM to .INFO and search engines has indexed domain with .COM TLD as well.

Try search for 'hacktutors.info' in Google. And also 'hacktutors.com'. In my case, when I search for 'hacktutors.info', it shows 7 well structured site links, but when I search for 'hacktutors.com', it shows link only compact site links. Why is this?

Can anyone with experience can explain me?

Yeah that would hurt you initially but if you manage them smartly then that could help you to achieve your target of porting to .com domain and as far as structured links is concerend I suppose .info is aged domain so it has more count than .com domain.
Here is what I would do ;)

redirect .info/xyz to .com/xyz (each and every link manually ) and start posting new posts on .com only.

All the best for .com porting

Sure things will not be as before, but as time passes and you have done well with redirects(from inner pages as well) google will eventually "catch up" .

This is a good thread. Let me ask this as well. Am I correct to think that he should keep the .info domain so he can keep the forward to the .com for long term?

Sure......