Previosu overstay of nearly 3 years .. Can I hope for EC?

My query is about Tier-2 visa. I used to live in UK (entry was via student visa during 2009 and completed PGD) now back home (bangladesh) for 1 year. I am thinking to apply for Tier-2 visa. But I have a problem which is over staying in UK for nearly 3 years and while returned to home I didn't withdraw my passport from UKBA because managed a travel permit from my embassy. So am I allowed to apply for Tier-2 visa? Hope I have explained my case properly & now waiting for reply. Thanks.

Do you have a sponsor?

thanks. I have no sponsor yet as haven't search for that seriously. i am really concern about my over staying matter. Does this effect on my application ?

Refusal under 320(7B)(a) for failing 320(7B)(i) possible, I think.
And, since you left without trying to get your passport back, who knows if HO had issued any notices against you (depending on why you had to leave UK without bothering to get your passport back) that you remain unaware of!