I am currently unable to sell any Larceny objects to Delvin Mallory, I have completed the entire thieves guild arc and all of the radiant city quests and still cant sell them.

Is this a bug or is there someone else I can give them to?

Additionally every time I picked one up the white text would show up saying I need to bring them to Delvin but there is no dialogue option to sell them.

It is a bug that have as well. You cannot sell any larceny targets to Delvin once you complete "Darkness Returns".

I also am facing the same glitch. Unfortunately since completing "Darkness Returns" I can't turn in larcency material OR get my last City Influence Quest.

Make sure you send an official ticket to Bethesda Soft so it gets looked at.

Go to
http://support.gamesas.com/eng/faqs.asp

and click the button email.

Thanks for the info!!!