Without citing its sources, German business monthly Manager Magazin said the US Federal Trade Commission had told Praxair management it planned to greenlight the tie-up and that a formal, written approval would follow “in the coming days”.

Linde’s share price leapt 6.3% to trade at 220.50 euros by 0845 GMT in Frankfurt, against a DAX blue-chip index up 0.4%.

A Linde spokesman declined to comment on the report when contacted by AFP.

The proposed merger between Linde and its US rival Praxair aims to create the world’s largest industrial gases firm with annual revenues of more than US$30 billion, overtaking France’s Air Liquide.

Major regulators have already given the all-share merger the go-ahead, including those from the European Commission, China and South Korea.

But the 68-billion-euro deal hit an unexpected snag when the US FTC demanded bigger concessions from both firms to assuage competition concerns, forcing them to sell off more assets than they had intended.

The clock is ticking on the deal as German law requires that all clearances need to be in by October 24, or the merger will fall through.