New phone company is born (3)
I believe the answer is:
nee
'is born' is the definition.
('nee' is 'born' in French)
'new phone company' is the wordplay.
'new' becomes 'n' (abbreviation as in New Testament NT).
'phone company' becomes 'EE' (British mobile network EE).
'n'+'ee'='NEE'
(Other definitions for nee that I've seen before include "Born (indicating a woman's maiden name)" , "Indicates the maiden name of a married woman" , "Word used to indicate family name of a married woman" , "Used to indicate the maiden name of a married woman" , "indicate old name" .)