KIEV, Oct. 28 - Naftogaz Ukrayiny, Ukraine’s national energy company, will have to pay about $1 billion to Gazprom of Russia before Nov. 7 for gas imported in October, Yuriy Kolbushkin, deputy chairman at Naftogaz, said Thursday.

This is the largest monthly gas bill that Ukraine has had to pay Gazprom so far this year, indicating that imports of Russian gas have been growing ahead of the upcoming winter. Ukraine’s average monthly bill so far this year was about $700 million.