WARSAW, Nov 10 (Reuters) - Poland's dominant gas company PGNiG said its biggest supplier, Russia's Gazprom , had proposed increasing prices for its gas in an existing long-term delivery deal.

State-run PGNiG, which has said it will not renew the deal that runs until 2022, said in its statement late on Monday that the proposal to renegotiate the price was groundless.

Gazprom's exporting arms, Gazprom Export, declined to comment.

PGNiG, which earlier this month asked Gazprom to lower the delivery price, imports most of the gas it resells from Gazprom based on its existing long-term deal.

Poland has sought to reduce reliance on Gazprom.

Gazprom and PGNiG have had a long-running dispute over gas prices. PGNiG has repeatedly said it pays more than its European peers for Gazprom's gas. (Reporting by Agnieszka Barteczko; Additional reporting by Vladimir Soldatkin in Moscow; Editing by Edmund Blair)