SPP said the amount of gas in storage and its diversified supplies were grounds for optimism its customers would not face disruptions this winter, but added it was vital for the European market and cross-border connections to remain functional.

"A contract with a strategic partner that ExxonMobil is opens new opportunities in access to natural gas and LNG," SPP said in a statement, without giving the volumes or price of the deal.

It said transport arrangements to the landlocked central European country had been secured from LNG terminals in Italy and Croatia.

Slovakia uses around 5 billion cubic metres of gas per year and has mostly been served by Russian gas pumped through Ukraine. Russia has reduced supplies to Europe this year in retaliation for Western sanctions over its invasion of Ukraine.

But Slovakia has secured extra supplies of LNG and piped gas from Norway, which it said would cover most of the needs of SPP, which serves around two thirds of the Slovak market.

(Reporting by Jan Lopatka; Editing by Mark Potter)