KIEV, May 26 ??“ Naftogaz Ukrayiny, the national oil and gas company, on Friday cited a January agreement with Gazprom, Russia??™s state-controlled gas monopoly, seeking to prevent an 18.2% hike in gas prices in July.

The development shows Naftogaz has been warning Gazprom that the key agreement may be undermined should the Russian company press ahead with the price hike starting from July 1, analysts said.