Russia had cut all its exports of electricity to Finland on Monday, flow data showed, after Russian utility Inter RAO said last week it would halt them because it had not been paid.
Inter RAO said on Friday it would stop exporting power to Finland from Saturday 1 a.m. local time (2200 GMT on Friday) "for the time being" as it had not been paid for power sold via pan-European exchange Nord Pool since May 6.
Finnish grid operator Fingrid, which said Moscow supplied about 10% of Finland's needs, said it could replace Russian supplies with Swedish power and by boosting domestic production.
It said the issue was related to Western sanctions that affected payments, rather than being retaliation for any other action by Finland, which was criticised by Moscow for saying it would seek to join NATO, a move Russia has long opposed.
"Due to these restrictions payments for sold Russian electricity can no longer be made. The suspension is therefore rather a consequence than a Russian countermeasure," Fingrid said, without making reference to the NATO decision.
Flows of Russian power to Finland on Monday were down to nil, data from grid operator Fingrid showed. They fell from 87 megawatts to zero early on Saturday.
Fingrid said last month it had prepared for the prospect of Russia cutting electricity flows to Finland by restricting the transmission capacity by a third.
Refinitiv analysts said the loss of Russian flows would drive up Finnish wholesale power prices by 8.20 euros to 90.20 euros per megawatt hour (MWh) for the third quarter.