It would seem that it isn’t all just smooth sailing for Fiat Chrysler and the PSA Group with regards to their merger plans.

EU antitrust regulators are now reportedly concerned about the two carmakers’ combined high market share in small vans, which could result in concessions being made in order for their $50 billion merger to go through, according to people familiar with the matter.

The two companies, which are seeking to combine into the world’s fourth biggest automaker, were told of the European Commission’s concerns last week.

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Now, it is up to FCA and PSA to dispel the European Commission’s doubts while also offering concessions, which is something they need to do in the next two days – otherwise, the merger deal could be hit with a four-month long investigation, as per Autonews Europe.

EU regulators have so far refused to comment on the matter, while FCA and PSA had no immediate comments, although word from the two camps will likely get out soon.

Separating these overlapping businesses, which is usually a regulatory demand aimed at ensuring more competition, could be tricky for the two companies because of technicalities. Still, both carmakers intend to go through with the merger in order to shoulder the cost of making cleaner vehicles, among other things.

Once the deal goes through, all of the following brands will fall under one roof: Abarth, Alfa Romeo, Citroen, Chrysler, Dodge, DS, Fiat, Fiat Professional, Jeep, Lancia, Opel, Ram, Maserati, Peugeot, Vauxhall.