Poland’s energy company PGNiG said it will receive $1.5 billion from Gazprom as reimbursement for overpayment in gas supplies in the period of 2014-2020, Kallanish Energy reports.

The companies signed an annex to their long-term Yamal contract a day earlier, under which they confirmed the application of a new pricing formula, as set out in an arbitration award in March. PGNiG announced the signing of the annex but didn’t disclose details on the new formula.

The company has won a claim at the Stockholm arbitration tribunal against Gazprom’s uncompetitive pricing formula. The award determined a revision on the formula to be more aligned with western European markets.

“When signing the annex, we agreed that the overpaid amount, estimated at some $1.5 billion (PLN 6.2 billion), would be transferred into PGNiG’s account by July 1st, 2020,” said President of the Management Board of PGNiG, Jerzy Kwieciński, in the statement.

The reimbursement covers supplies from November 2014 to February 2020. PGNiG didn’t disclose details of the pricing formula.