The European Commission is warning Linde and Praxair that getting their planned $80 billion industrial gas tie-up past European competition rules may mean selling off major parts of the combined business. The EC says it is concerned that the merger may reduce competition in the supply of crucial industrial gases, including oxygen, carbon dioxide, and helium. The merger would reduce the number of major European suppliers of these and many other gases to just three. And the high level of investment needed to establish a meaningful market position means that new entrants to the sector are unlikely, according to the EC. It has begun an in-depth investigation that may run until July 4. The EC approves the vast majority of mergers following a routine review. Five other in-depth investigations are currently underway, of which three feature chemical companies: the proposed acquisition of Monsanto by Bayer, the formation of an acetate joint venture by Celanese and Blackstone, and the proposed purchase of Cristal by Tronox.