De or het telecomfusie?

The correct Dutch article is:

de telecomfusie

Rule Words ending in -tie and -sie: almost always de. See the rule

How to use telecomfusie

the telecomfusiede telecomfusie
this telecomfusiedeze telecomfusie
that telecomfusiedie telecomfusie
our telecomfusieonze telecomfusie
your telecomfusiejouw telecomfusie
every telecomfusieelke telecomfusie
which telecomfusie?welke telecomfusie?
a big telecomfusie / the big telecomfusieeen grote telecomfusie, de grote telecomfusie