PARIS– European antitrust authorities appear poised to withhold immediate approval of the purchase by Airbus Safran Launchers of the French government’s stake in launch-service provider Arianespace pending an investigation that could last for several months, European industry officials said.

The investigation by the European Commission’s Competition Directorate-General (DG-Comp) appears to have been slowed by concerns that the Airbus satellite manufacturing division could get preferential treatment by an Airbus Safran Launchers-owned Arianespace unless specific preventive measures were taken.

Airbus Safran Launchers is intended as a 50-50 joint venture between Airbus Defence and Space and Safran, whose Snecma division builds Ariane rocket motors.

The French government in January formally signaled its approval of the sale of its 35 percent Arianespace stake, held by the French space agency, CNES, to Airbus Safran Launchers for 150 million euros ($163 million).

The company submitted the transaction to DG-Comp for approval on Jan. 8. The commission typically gives itself 25 working days to respond, during which time it seeks input from the affected company’s partners, customers and competitors.

On Feb. 5, Airbus Safran Launchers submitted antitrust-related guarantees to the commission, which had sent a provisional decision deadline of Feb. 26 under its Phase I investigation deadline.

A decision to proceed with a deeper Phase II investigation would add up to three or four months to the process, if not longer.

Thales Alenia Space of France and Italy, a major satellite producer, had raised preferential-treatment concerns in 2014 and 2015 when Airbus Safran Launchers was being created.

Thales Alenia Space Chief Executive Jean-Loic Galle specifically asked French government authorities to assure that there was a “Chinese Wall” between Airbus Safran Launchers and Arianespace on the one hand, and Airbus’s satellite division on the other.

A satellite builder will often trade proprietary technical information with a launch-service provider, and sometimes pricing information as well, in the months preceding a launch.

Galle has said in recent months that Thales Alenia Space is now satisfied that the future Arianespace shareholding structure will protect the secrets of Airbus satellite competitors just as it has in the past. Airbus has been a major industrial shareholder of Arianespace for years.

A Thales Alenia Space official on Feb. 19 confirmed that the company’s position had not changed and that it has no objections to the Airbus Safran Launchers takeover of Arianespace.

The global nature of the commercial launch business means that any assessment for anti-trust purposes must seek the opinion of non-European actors, especially since there is only one European launch provider.

Arianespace launch-service competitors include SpaceX of the United States, International Launch Services – also of the United States, but marketing Russia’s Proton rocket – and Mitsubishi Heavy Industries of Japan, which operates the H-2A rocket.

On the satellite side, Airbus’s competitors, in addition to Thales Alenia Space, include Space Systems/Loral of Palo Alto, California; Boeing Space and Intelligence Systems of El Segundo, California; Orbital ATK of Dulles, Virginia; Mitsubishi Electric of Japan; and Lockheed Martin Space Systems of Sunnyvale, California.

Among customers, the top satellite fleet operators would be consulted as well on whether they saw any potential market distortion in the Airbus Safran Launchers transaction.

Satellite fleet operator Eutelsat of Europe, which in the past decade has been the biggest single corporate customer of Arianespace, on Feb. 17 said it told the commission that Eutelsat supported the Airbus Safran Launchers transaction.

“We applaud the decision of two large industrial players, Airbus and Safran, to unify their forces to take control of Arianespace and develop it commercially given the tough competition from American and Russian launchers,” Eutelsat Chief Executive Michel de Rosen said in a conference call with journalists on the company’s quarterly earnings results.

“It seems there are several complications in Brussels, and that the commission has decided to deepen its analysis of the project,” de Rosen said, referring to the Belgian headquarters of the European Commission. “We told the commission that we consider there is no conflict of interest.

“Airbus is both a satellite manufacturer and the co-shareholder of this new company [Airbus Safran Launchers]. Airbus is already a big Arianespcae shareholder and has been for years. For us this is a non-issue. But apparently there are conflicting opinions about this.”

A delay at the European Commission will have an effect on the near-term management of Arianespace but will have no effect on progress on the next-generation Ariane 6 launcher, whose development prompted the formation of Airbus Safran Launchers.

Airbus has said the new company’s full formation is pending a French tax assessment of the planned 800 million euros in cash that Safran has agreed to pay to secure a 50 percent stake in the new joint venture.

DG-Comp had approved the creation of Airbus Safran Launchers in November 2014 after the two companies agreed that Safran’s satellite electric-propulsion business would be kept out of the joint venture for 10 years.