Amazon.com Inc has filed a legal challenge at an Indian tribunal against the national antitrust agency’s supension of a 2019 deal it had with Indian retailer Future Group, two sources with direct knowledge told Reuters on Sunday.

India’s antitrust agency suspended its approval of Amazon.com’s 2019 deal with Future Group last month, potentially denting the U.S. e-commerce giant’s attempts to block the sale of Future’s retail assets to an Indian market leader.

The suspension has jolted Amazon as it subsequently led to a halt in the arbitration proceedings between the two sides in a long-running commercial dispute.

Amazon has long argued that Future violated the terms of its 2019 deal in deciding to sell retail assets to market leader Reliance Industries , and the U.S. company’s position had so far been backed by the Singapore arbitrator and Indian courts. Future denies any wrongdoing.

But the Competition Commission of India (CCI) last month suspended that deal saying Amazon suppressed information while seeking clearances for the deal back then.

Amazon filed an appeal against CCI’s decision at India’s National Company Law Appellate Tribunal late on Saturday night, the two sources said.

The appeal will be heard later this week, said one of the persons.

Amazon did not immediately respond to a request for comment. The CCI also did not respond.