The Finnish subsidiary of Russian state-owned energy provider Inter RAO has announced a halt in electricity supplies to Finland as of May 14 over unpaid bills.
But the timing of the cutoff points to Moscow anger over its northwestern neighbor's sudden abandonment of neutrality to join the NATO alliance since Russia invaded Ukraine.
The Finnish subsidiary, RAO Nordic, said it hadn't received payments for energy provided through the Nord Pool power exchange since May 6.
"This situation is exceptional and happened for the first time in over 20 years of our trading history," RAO Nordic said.
The import cutoff will go into effect at 1 a.m. local time on May 14 (2200 GMT/UTC on May 13), according to Finnish grid operator Fingrid, which warned weeks ago of the possibility of a suspension.
Fingrid said Finnish households and other consumers were safe and that Russian power accounts for only around 10 percent of the country's consumption.
"Missing imports can be replaced in the electricity market by importing more electricity from Sweden and also by domestic production," Fingrid said.
Unprecedented sanctions against Russian financial, diplomatic, and commercial interests over the unprovoked aggression against Ukraine have crippled many trade and other flows between Russia and the West.
Last month, Russian officials announced a cutoff of natural gas supplies to EU and NATO members Poland and Romania, which have lent considerable support to Ukraine since the invasion began in late February.
It cited their refusal to pay in rubles for supplies contracted in euros or other non-Russian currencies.
RAO Nordic has cited problems collecting payments from Nord Pool, according to Fingrid.
"Nord Pool is the one paying for them. Fingrid is not a party in this electricity trade. We provide the transfer connection from Russia to Finland," Reima Paivinen, a Fingrid executive, told Reuters.
A Nord Pool spokesman confirmed that settlements had always been in euros or Norwegian, Swedish, or Danish currencies but never rubles, "in line with our standard procedures."