Germany's Linde and US rival Praxair on Friday cleared the final regulatory hurdle to complete their hard-fought mega merger, creating the world’s largest industrial gas maker.

They will now officially be run as one combined company after finalising the last asset sales required to satisfy US competition concerns, Linde PLC, as the new group will be known, said in a statement.

The two companies had already won a conditional green light for their tie-up back in October but had to continue operating as separate entities until the divestments of nine American business units were completed.

Those restrictions "have been lifted" now that the group has met the demands of the US FederalTrade Commission, Linde said.

"The company will now fillly integrate its business globally."

With joint annual revenues of 24 billion euros ($28 billion), some 80,000 employees and a market capitalisation of 78 billion euros, the group overtakes France's Air Liquide to become the industry's global leader.

But the tie-up, first announced in 2016, came at a steeper-than-expected cost with global regulators demanding more divestments than Linde and Praxair had originally planned for - eating into their projected savings and making the deal more painful.