(Reuters) — Chipmaker Qualcomm Inc said it was asked to refund Canada’s BlackBerry Ltd a sum of $814.9 million in an arbitration settlement over royalties for certain past sales.

U.S.-listed shares of BlackBerry were up about 16 percent at $8.94 in heavy premarket trading. Qualcomm was down about 1 percent at $54.81.

The companies in 2016 decided to arbitrate a dispute over Qualcomm’s agreement to cap certain royalties applied to payments made by BlackBerry under a licensing deal.

Qualcomm said on Wednesday it does not agree with the decision of an arbitration panel, but the payment is binding and not appealable.

Qualcomm is also fighting a lawsuit filed by Apple Inc, accusing the company of overcharging for chips and refusing to pay some $1 billion in promised rebates.

The U.S. government has accused Qualcomm of resorting to anticompetitive tactics to maintain a monopoly over key semiconductors in mobile phones.

BlackBerry said a final award including interest and reasonable attorneys’ fees will be issued after a hearing on May 30.

Sullivan & Cromwell LLP represented BlackBerry in the proceeding.

(Reporting by Ahmed Farhatha in Bengaluru; Editing by Sriraj Kalluvila and Maju Samuel)