Linde and Praxair have entered into a definitive agreement to come together under a new holding company through an all-stock merger of equal transaction.

Linde and Praxair expect the transaction to close in the second half of 2018, subject to customary closing conditions, including regulatory approvals.

The proposed merger brings together two companies in the global industrial gas industry. The combined company will have a strong presence in global and end-markets, which it said would result in a more diverse and balanced global portfolio as well as increased exposure to long-term macro-economic growth trends.

“This combination is a compelling and transformative opportunity to create a world-class leader in the industrial gas industry,” said Steve Angel, Chairman and CEO of Praxair.”

“This merger is a once-in-a-lifetime opportunity to form a great global industrial gas company poised to deliver value for customers, employees and shareholders alike. The new company is well positioned in all key markets and regions and can build on its exceptional R&D expertise,” said Aldo Belloni, CEO of Linde.

The combined company, also named Linde and worth about $70bn, will form a new holding company based in Ireland.

Corporate functions are to be split between Danbury, Connecticut and Munich, Germany. The group said it expects synergies of $1.2bn a year from the merger, to be achieved within three years.