iron out something – to put something into a finished state by solving problems, removing differences, or taking care of details [Cambridge dictionary]
A ‘merger’ is when two or more companies combine to make one larger company. 🤓
So, this sentence means that the company has made the decision to join with another to make one larger company, but hasn’t decided exactly how and when it’s going to happen. 😊
‘Iron out something’ is a very useful phrasal verb for Business English as we often need to ‘iron out’ terms or details of a contract or an agreement.