Lundin Mining and INMET Mining have terminated an agreement made in January to merge and create a new international copper-producing entity, the companies have announced.

Both firms have agreed that Inmet’s right to a break fee of $120m will be preserved in connection with an unsolicited offer by Equinox Minerals to acquire Lundin Mining.

Lundin Mining president and CEO Phil Wright, and Inmet Mining president and CEO Jochen Tilk, said both firms believe the merger would have created a leading copper producer with benefits for both firms.

“We have, however, agreed to mutually terminate the agreement on the grounds that we could not reach a position that we thought would be supported by both companies’ shareholders,” they said in a joint statement.