Used for formal or serious cancellations, especially engagements, business negotiations, or contracts. Often implies a breakdown in relations.
The merger negotiations between the two companies fell through.
The engagement was broken off.
破談 refers to the cancellation of an arranged matter like a marriage or contract, whereas 物別れ is used more broadly for failed negotiations or discussions.
破談 means an engagement or deal being called off, while 破綻 means a system, finances, or relationship collapsing under its own strain; they sound alike but refer to different kinds of failure.
Compound of 破 (ha, 'break, destroy') and 談 (dan, 'talk, discussion'), literally meaning 'broken talks'. The term has been used since at least the Meiji period to refer to the failure of formal negotiations or engagements.