By Marek Strzelecki and Pavel Polityuk

WARSAW, April 8 (Reuters) - Poland's Orlen PKN.WA aims to sell 10 cargoes of LNG to Ukraine this year as Kyiv seeks to fill gas storage sites ahead of winter, two sources close to the matter told Reuters.

Ukraine is aiming to expand gas transit routes and buy large volumes of U.S. LNG via Germany, Greece, Lithuania and Poland after being left with almost empty storage and damaged production facilities after Russian shelling.

The sources said that Orlen supplies include gas from the United States, which has called on Europe to buy more of its energy and also provides key military and financial support for Ukraine.

Orlen wants to sell up to 1 billion cubic metres (bcm) of gas, or 10 cargoes, to Ukraine by September, including two cargoes already sold to state-controlled Naftogaz.

In addition to Naftogaz, Orlen is discussing the issue of liquefied gas supplies with Ukraine's largest private energy company, DTEK, one of the sources said. Orlen will buy cargoes for Ukraine on the spot market, the source added.

DTEK, Orlen and Naftogaz declined to comment.

Orlen's gas output surged 20% last year thanks to higher production in Norway. Combined with contracts for imports of LNG, and booked pipeline and regasification capacity, Orlen has access to more gas than Poland's domestic consumption.

Poland can supply up to 7 million cubic metres (mcm) of gas to Ukraine per day via the existing interconnector, the capacity of which will be increased by early 2026.

Ukraine has said it needs to import at least 4 bcm for the 2025/26 heating season, half of which could be LNG.

(Reporting by Marek Strzelecki and Pavel PolityukEditing by David Goodman)

((Marek.Strzelecki@thomsonreuters.com;))