Tell heads of regional engineering company of unusual new technology (7)
I believe the answer is:
recount
'tell' is the definition.
(synonyms)
'heads of regional engineering company of unusual new technology' is the wordplay.
'heads of' says to take the initial letters.
The first letters of 'regional engineering company of unusual new technology' is 'RECOUNT'.
(Other definitions for recount that I've seen before include "Communicate" , "post-election procedure?" , "Check numbers" , "Go over details" , "Tell - check on election result" .)