The package aims to step up pressure on financial and logistics networks helping the Kremlin in its war in Ukraine. One of Russia's largest insurers, Rosgosstrakh, was also targeted.
"These sanctions target the vessels, the money and the actors propping up Russia's war economy, and in turn, threatening European security," said Prime Minister Keir Starmer, who was attending a Group of Seven summit in France.
The measures cover more than 20 oil tankers and several liquefied natural gas vessels. Britain said it was the first time a G7 country had sanctioned ships linked to Russia's Arctic LNG 2 project.
Neither the Russian Embassy in London nor Yandex immediately responded to requests for comment.
Russia's shadow fleet is a network of vessels registered elsewhere, many of them ageing, used to evade Western energy sanctions.
Britain has imposed sanctions on almost 600 such vessels, and on Sunday British commandos boarded and intercepted one of them, an oil tanker, in the English Channel.
The new sanctions also target what Britain described as a clandestine network centred on a firm called Neptune seeking to acquire Western technology for Russia's defence sector.
Britain said Neptune acted as a front for Russia's GRU military intelligence agency to source goods and technology.
The package targets individuals identified as GRU officers as well as companies operating in Russia and abroad accused of supplying defence technology.
with PA
