Formed a union started by takeover apparently (7)

'formed a union' is the definition.
The definition and answer can be both to do with contact as well as being past participle verbs.
Perhaps there's a link between them I don't understand?

'started by takeover apparently' is the wordplay.
'started by' says to put letters next to each other.
'takeover' becomes 'coup' (I've seen this in another clue).
'apparently' becomes 'led' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'coup' put next to 'led' is 'COUPLED'.

Can you help me to learn more?