The £200,000 ($249,000) fine, announced Friday, came after Ofcom ruled RT had failed to maintain “due impartiality” in seven programs that aired in March and April last year.
Ofcom directed the Russian broadcaster to air a summary of the ruling, which was originally handed down in December.
The programs were broadcast after the poisoning of former Russian double agent Sergei Skripal and his daughter. UK authorities said they were the victims of an attack conducted by agents of the Russian military intelligence service, the GRU.
“We consider this sanction to be appropriate and proportionate. It takes into account the additional steps that RT has taken to ensure its compliance,” Ofcom said in a statement on Friday.
RT said it was “very wrong” for Ofcom to issue the fine. “We find the scale of proposed penalty to be particularly inappropriate,” the network added in a statement.
The Russian network has launched a legal challenge to Ofcom, which has the authority to cancel broadcasting licenses. The regulator said that the fine would be enforced once the legal case had concluded.
RT, whose ratings are tiny in the UK, is owned by Russian state-owned news agency RIA Novosti. RT’s UK broadcast licenses were granted to the company’s television division, ANO TV Novosti.
— An earlier version of this story incorrectly said the Skripals had been killed.