Information provided by corporation blocked by old employee (8)
I believe the answer is:
factotum
'employee' is the definition.
(I've seen this before)
'information provided by corporation blocked by old' is the wordplay.
'information' becomes 'fact' (fact is a kind of information).
'provided by' means one lot of letters go next to another.
'corporation' becomes 'tum' ('corporation' is a humorous term for stomach fat).
'blocked by' is an insertion indicator (block can mean to plug a gap in something).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'fact'+'tum'='facttum'
'facttum' going around 'o' is 'FACTOTUM'.
(Other definitions for factotum that I've seen before include "Person employed to do all sorts of work" , "Person employed for all kinds of work" , "Versatile employee" , "Employee with a variety of jobs" , "Jack of all Trades" .)