KIEV, Ukraine, Oct. 6 (UPI) -- Natural gas to be transferred to Russia's Gazprom will count as $600 million in credit against the more than $1.3 billion debt owed by Ukraine, a report said.

The debt was incurred as companies working in Ukraine failed to pay Gazprom for natural gas stored in Ukrainian underground tanks, Ukrainian Fuel and Energy Minister Yuri Boiko said in a interview Saturday.

A protocol to be signed Monday transfers $600 million in gas from Ukraine to Gazprom with settlement terms for the rest of the debt yet to be determined, Itar-Tass reported Saturday.

Gazprom Friday told its European partners gas supplies for Ukrainian consumers would be reduced if the Ukrainian government did not reach a settlement agreement in October, Itar-Tass said.