Linde AG and Praxair Inc.’s (PX) planned $47 billion merger could be in jeopardy after the Federal Trade Commission’s (FTC) calling for the sale of more assets. Praxair shares were down 5.9% in early trade Monday. The merger would create the largest supplier of industrial gases in the world, ahead of current market dominator France-based Air Liquide SA. But, the FTC said it wanted the companies to shed more assets to ease its antitrust concerns before it approved the deal.

Linde, based in Munich, Germany, said it expected those demands have a “high probability” of exceeding a limit to asset sales per the terms of the deal. It said the latest demands are “more onerous than previously expected.”

The companies have a deadline of Oct. 24 to close the asset sales they have already announced, but Kepler Cheuvreux analysts said that there is a “very high” likelihood that the companies will miss that deadline, although they said the FTC’s new threshold on assets is not necessarily a deal breaker. “The talks with the FTC about the necessary divestiture commitments are being continued with the aim to achieve an acceptable outcome for all involved,” Linde said in a statement.

Role of Assets in Merger

Linde and Praxair produce gases like oxygen and nitrogen that are used commercially in hospitals and factories. They have agreed to a deal that includes the sale of assets that have less than 3.7 billion euros ($4.3 billion), but the FTC’s latest requirement would require they exceed that. So far, Linde has already agreed to sell its North American assets, with combined 2017 revenue of an estimated $1.7 billion annually. The companies have also both agreed to sell some industrial plants in Europe.

Linde and Praxair attempted a merger two years ago, but it was thwarted by German unions concerned about job cuts. (See also: Praxair, Linde AG Merger.)