US fertilizer company CF Holdings has called off its planned $8 billion merger with Dutch rival OCI, the latest deal to fall foul of new US tax inversion rules. “The Treasury announcement on Apr. 4, 2016 materially reduced the structural synergies of the company,” both companies said in an official statement.

Inversion deals have been popular as US companies seek to benefit from more favorable tax regimes overseas to reduce their corporate tax liabilities. However, the US introduced new rules to curtail the practise in April, forcing major US drugmaker Pfizer to abandon its proposed $150 billion merger with Ireland’s Allergan.

“Although the original deal created significant value for both parties, changes in the regulatory and commercial environments forced us to reevaluate the combination and led us to the conclusion that terminating the agreement is in the best interests of CF Industries and its shareholders,” said Tony Will, CF Industries president and CEO.

CF Industries and OCI had initially planned to register the combined company in the UK, although they later agreed to move the tax residency to the Netherlands to satisfy the US’ tougher inversion laws.

The deal, which would have seen CF Industries acquiring the European and North American operations of OCI as well as its global distribution assets, would have created the world’s largest publicly traded nitrogen company.

Following the merger’s collapse, CF Industries will now pay OCI a termination fee of $150 million.